Khmer orthography notes

Sample

Select part of this sample text to show a list of characters, with links to more details.
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មាត្រា ១ មនុស្សទាំងអស់ កើតមកមានសេរីភាព និងសមភាព ក្នុងផ្នែកសេចក្ដីថ្លៃថ្នូរនិងសិទ្ធិ។ មនុស្ស មានវិចារណញ្ញាណនិងសតិសម្បជញ្ញៈជាប់ពីកំណើត ហើយគប្បីប្រព្រឹត្ដចំពោះគ្នាទៅវិញទៅមក ក្នុង ស្មារតីភាតរភាពជាបងប្អូន។

មាត្រា ២ មនុស្សម្នាក់ៗ អាចប្រើប្រាស់សិទ្ធិនិងសេរីភាពទាំងអស់ ដែលមានចែងក្នុងសេចក្ដីប្រកាសនេះ ដោយគ្មានការប្រកាន់បែងចែកបែបណាមួយ មានជាអាទិ៍ ពូជសាសន៍ ពណ៌សម្បុរ ភេទ ភាសា សាសនា មតិនយោបាយ ឬមតិផ្សេងៗទៀត ដើមកំណើតជាតិ ឬសង្គម ទ្រព្យសម្បត្ដិ កំណើត ឬស្ថានភាព ដទៃៗទៀតឡើយ។ លើសពីនេះ មិនត្រូវធ្វើការប្រកាន់បែងចែកណាមួយ ដោយសំអាងទៅលើឋានៈខាងនយោបាយ ខាងដែនសមត្ថកិច្ច ឬខាងអន្ដរជាតិរបស់ប្រទេស ឬដែនដីដែលបុគ្គលណាម្នាក់រស់នៅ ទោះបីជាប្រទេស ឬដែនដីនោះឯករាជ្យក្ដី ស្ថិតក្រោមអាណាព្យាបាលក្ដី ឬគ្មានស្វ័យគ្រប់គ្រងក្ដី ឬស្ថិតក្រោមការដាក់ កម្រិតផ្សេងទៀតណាមួយ ដល់អធិបតេយ្យភាពក្ដី។

Source: Unicode UDHR, articles 1 & 2

Usage & history

6thC – today

Phoenician

└ Aramaic

└ Brahmi

└ Tamil-Brahmi

└ Pallava

└ Khmer

+ Cham

+ Kawi

+ Mon-Burmese

+ Grantha

+ Tamil

The Khmer script is used for writing the official language of Cambodia, and sometimes for Cambodian minority languages, such as Tampuan, Krung, Cham, Brao and Mnong. It is currently in widespread use, although it is estimated that 35% of the Khmer-speaking population aged 15 and over are illiterate in the script. It is also used to write Pali in the Buddhist liturgy of Cambodia and Thailand.

អក្សរខ្មែរ ʔaʔsɑː kʰmaːe Khmer script

The script is thought to be descended from the Brahmi Pallava script, and the Khmer literary tradition dates back to the 7th century. The modern Khmer script differs somewhat from precedent forms seen on the inscriptions of the ruins of Angkor. The Thai and Lao scripts are descended from an older form of the Khmer script.

Sources: Scriptsource, Wikipedia, Unicode13 ^p653

Basic features

The script is an abugida, ie. like most Brahmi-influenced scripts, each consonant carries with it an inherent vowel. See the table to the right for a brief overview of features for the modern Khmer orthography.

Khmer text runs left to right in horizontal lines. Words are not separated by spaces, however words may be separated by ZWSP. Spaces are used as phrase separators.

❯ consonantSummary

Modern Khmer uses 33 basic consonants, and 10 special character combinations are used for foreign sounds.

Each onset consonant is associated with a high or low class related to pronunciation (there is no tone). Khmer has more vowel sounds than ways to write them, so the choice of consonant class indicates different sounds for the same written vowel. Other factors may also affect the sound, such as stress, vowel harmony, and diacritics.

Word-internal clusters are very common at the beginning of a word, but clusters also occur medially in multisyllable words, and occasionally at the end of a word (though the 2nd consonant at the word end is usually not pronounced). Clusters are indicated by stacked consonants. Subjoined forms are created using an invisible coeng character. Stacks do not span word boundaries.

Word-final consonant sounds (typically 8 consonants and characters) use ordinary code points without an inherent vowel. Because there are no spaces or other word dividers, it is difficult to detect boundaries algorithmically. Two word-final sounds (m and h) can be produced using combining marks.

❯ basicV

The Khmer orthography is an abugida with 2 inherent vowels (for example, using the two symbols for the sound k, ក is kɑː neck, and គ is kɔː mute).

Other post-consonant vowels are written using 21 vowel sign or other combining marks and 2 glide consonant letters. Two additional diacritics are used to change the register of a syllable.

Khmer has more vowel sounds than ways to write them. Therefore, a written vowel can have different pronunciations, depending on the class of the base consonant. (There is no tone in Khmer, so classes are specially designed for vowel selection.) Additional factors include whether this is an unstressed vowel, vowel harmony, and whether any of the special diacritics have been used to change the sound. For an in-depth treatment of pronunciation see Huffman in the sources section.

There are 3 pre-base glyphs and 5 circumgraphs, 2 of which can decompose into multipart vowels. This page lists 15 multipart vowels (made from 9 vowel signs, and 8 consonants/diacritics), not counting decompositions. Multipart vowels can involve up to 3 glyphs, but only surround the base consonant(s) on 2 sides, eg.កោះ koh̽

Standalone vowel sounds are typically written using vowel signs applied to 17A2, but there is also an incomplete set of independent vowels.

Modern Khmer has a number of distinct font styles, including slanted (called អក្សរច្រៀង), which has an upright variant, and round (called អក្សរឈរ). The round style includes more ligated forms. The upright style is used here.

Character index

Letters

Show

Basic consonants

ផ␣ប␣ត␣ថ␣ឋ␣ដ␣ច␣ឆ␣ក␣ខ␣អ␣ព␣ភ␣ទ␣ធ␣ឍ␣ឌ␣ជ␣ឈ␣គ␣ឃ␣វ␣ស␣ហ␣ម␣ន␣ណ␣ញ␣ង␣រ␣ឡ␣ល␣យ

Independent vowels

ឥ␣ឦ␣ឪ␣ឧ␣ឩ␣ឯ␣ឰ␣ឱ␣ឳ␣ឲ

Vocalics

ឫ␣ឬ␣ឭ␣ឮ

Other

ៗ

Not used for contemporary Khmer

ឣ␣ឤ

ឨ␣ឝ␣ឞ

ៜ

Combining marks

Show

Vowel signs

េ␣ែ␣ៃ␣ៀ␣ឿ␣ើ␣ោ␣ៅ␣ួ␣ុ␣ូ␣ិ␣ី␣ឹ␣ឺ␣ៈ␣ា␣័␣៏␣ំ␣ះ

Other

្␣៍␣់␣៉␣៊␣៑␣៌␣៝␣៎

Not used for Khmer

឴␣឵

Numbers

Show

០␣១␣២␣៣␣៤␣៥␣៦␣៧␣៨␣៩

Punctuation

Show

“␣”␣‘␣’␣៖␣។␣៕␣៙␣៚

ASCII

(␣)␣,␣-␣.␣?␣!

Not used for Khmer

៘

Symbols

Show

៛

Other

Show

␣‌␣‍

To be investigated

%␣:␣;␣[␣]␣§␣«␣»␣ʼ␣͏␣‑␣–␣—␣†␣‡␣…␣‰␣′␣″␣‹␣›␣⁠

Phonology

These are sounds for the modern Cambodian language.

Click on the sounds to see where else in the document they are referred to.

Phones in a lighter colour are non-native or allophones. Source Wikipedia.

Vowel sounds

Plain vowels

	Front	Central	Back
Close	i iː	ɨ ɨː	u uː
Close-mid	e eː	ə əː	o oː
Open-mid	ɛː		ɔː
Open		a aː	ɑ ɑː

Complex vowels

	Front	Central	Back
Close	iə	ɨə	uə ŭə
Close-mid	ei ĕə	əɨ	ou ŏə
Open-mid			ɔə
Open		ae aə ao

Consonant sounds

	labial	dental	alveolar	palatal	velar	glottal
stops	p ɓ~b	t ɗ~d		c	k ɡ	ʔ
aspirated	pʰ	tʰ		cʰ	kʰ
affricates
fricatives	f		s z			h
nasals	m		n	ɲ	ŋ
approximants	ʋ~w		l	j
trills/flaps			r

	Labial	Dental	Alveolar	Palatal	Velar	Glottal
Stop	p pʰ ɓ~b	t tʰ ɗ~d		c cʰ	k kʰ	ʔ
Affricate
Fricative			s			h
Nasal	m		n	ɲ	ŋ
Approximant	ʋ~w		l	j
Trill/flap			r

Structure

Phonetic syllables

Many native Cambodian words are monosyllabic. `Khmer also has many bisyllabic words, in which the first syllable is typically unstressed, and the vowel is rendered in colloquial speech as a schwa. Some bisyllabic words are compounds, however, and this may not apply.

Syllables start with one or more consonants or an independent vowel, however the latter represent a vowel sound after a glottal stop, so the syllable onset is always C(C)(C)V. The rhyme is composed of a short vowel in stressed syllables that is always followed by a consonant (VC), or a long vowel, that may not be.

Many monosyllabic words begin with consonant clusters, and some monosyllabic words end with clusters, although only one consonant is pronounced in syllable final position.

Word-internally, a syllable with a final consonant followed by another syllable creates a stack of consonants. The top item in the stack is the syllable final consonant, and the initial consonant of the next syllable is rendered in subjoined form.

Polysyllabic words are usually of Sanskrit, Pali or French origin. These words tend to alternate stress across their syllables, but may not.

Orthographic syllables

An orthographic syllable differs from a phonetic syllable in that it always begins with a consonant, or cluster of consonants. Where word-medial stacks occur, the orthographic syllable may begin with the final consonant of the previous phonetic syllable and continue through the onset(s) of the following syllable. Alternatively, an orthographic syllable may be just a final consonant (or consonant cluster) in a phonetic syllable.

កដ្ឋមណ្ឌូ — The same word, split into phonetic syllables (left) and orthgraphic syllables (right).

An orthographic syllable includes all the combining characters associated with the consonants it contains.

Vowels

Dashes are used to indicate whether the character represents a vowel sound in a closed or an open syllable.

Vowel summary table

The following table summarises the main vowel to character assigments.

ⓘ represents the inherent vowel. Vowels in the left column show pronunciations after ɑ-class consonants, and the column to its right shows use for ɔ-class consonants. The right-hand column shows standalone vowels.

Simple:		ិ␣ី␣ ␣ឹ␣ឺ␣ ␣ុ␣់␣ូ	ឥ␣ឧ␣ឩ
	ិ␣ ␣ុ	េ␣ ␣ោ	ឧ
	ិ␣ឹ	ើ	ឥ
		ែ␣ ␣ⓘ
	័␣ៈ␣ា␣ ␣់␣ⓘ␣៏
Complex:	ៀ␣ ␣ឿ	ា␣ៀ␣ិះ␣េះ␣ ␣ឿ␣ៃ␣័យ␣ៅ␣ូវ␣ ␣ួ␣់␣ោះ␣ុះ␣ុំ␣ំ
	េ␣ិះ␣េះ␣ែះ␣ ␣ូ␣ុះ␣ុំ	ៈ␣័␣ា◌់␣ះ␣ាំង␣ ␣័␣ា◌់␣ាំ	ឩ
	ី␣ឺ␣័␣ឹះ␣ើះ␣ូវ	ិយ	ឥ␣ឦ␣ឪ
		័រ
	ោ␣ែ␣ើ␣ៃ␣័យ␣ៅ␣ះ␣ោះ␣ាំ␣ំ␣ាំង		ឯ␣ឧ␣ឱ␣ឲ␣ឰ␣ឳ
Vocalics:			ឫ␣ឬ␣ឭ␣ឮ

For additional details see vowel_mappings.

Here is the set of characters described in this section, grouped by general category.

ង␣យ␣រ␣វ␣ឥ␣ឦ␣ឧ␣ឩ␣ឪ␣ឯ␣ឰ␣ឱ␣ឲ␣ឳ

ា␣ិ␣ី␣ឹ␣ឺ␣ុ␣ូ␣ួ␣ើ␣ឿ␣ៀ␣េ␣ែ␣ៃ␣ោ␣ៅ␣ំ␣ះ␣ៈ␣់␣៏␣័

Consonant registers

Cambodian inherited a writing system that has more vowel sounds than ways to write them, but has fewer consonant sounds than consonant symbols. Khmer takes advantage of this by dividing the consonant symbols into 2 classes (or registers): an a-class and an ɔ-class. The class of a consonant then determines the vowel sound in a syllable. For example, compare the pronunciations in the table:

ɑ-class consonant	IPA	ɔ-class consonant	IPA
1780	kɑː	1782	kɔː
1780 17B8	kəj	1782 17B8	kiː
1780 17B6	kaː	1782 17B6	kiə

Examples of vowel pronunciation changes, depending on the class of the base consonant.

Other factors may also affect the sound, such as stress, and vowel harmony. Diacritics can also be used to change the class of a consonant, or create sequences that represent a class for which there isn't a single character (see register_change).

These registers are not related to tone, as Khmer is not tonal.

Vowel harmony

In two-syllable words, where the second syllable begins with one of the following sonorant consonants the vowel class of the second syllable is the same as that of the first.

ង␣ញ␣ណ␣ន␣ម␣យ␣ឡ␣ល␣រ␣វ

For example, in the following word the second syllable starts with an ɔ-class consonant but the class of the preceding syllable turns the vowel to an ɑ-class sound. There are, however, exceptions to this rule. ប្រយ័ត្ន

Inherent vowels

ក kɑː U+1780 KHMER LETTER KA

គ kɔː U+1782 KHMER LETTER KO

Khmer has 2 inherent vowels: ɑː and ɔː. Both are commonly transcribed as a.

The class of the consonant will initially dictate which sound is appropriate, eg. 1780 (an ɑ-class consonant) is pronounced kɑː whereas 1782 (an ɔ-class consonant) is pronounced kɔː, but see also vowel_harmony.

The invisible characters ឴ KIVAQ U+17B4 KHMER VOWEL INHERENT AQ and ឵ KIVAA U+17B5 KHMER VOWEL INHERENT AA were originally intended to represent a phonetic difference not expressed by the spelling, so as to assist in phonetic sorting, however, the Unicode Standard considers them insufficient for that purpose and errors in the encoding, and they should not be used.u,677

Post-consonant vowels

Other vowels that follow consonants are written using 21 vowel sign or other combining marks and 2 glide consonant letters. Two additional diacritics are used to change the register of a syllable.

In the âksâr mul font style, some vowel signs form ligatures with their base consonants. See vowel_ligatures.

Ten vowel signs are spacing marks, meaning that they consume horizontal space when added to a base consonant. The reahmuk described below is also a spacing mark.

An orthography that uses vowel signs is different from one that uses simple diacritics or letters for vowels in that the vowel signs are generally attached to the orthographic syllable, rather than just applied to the letter of the immediately preceding consonant. For example, pre-base vowel sign components are rendered before a whole consonant cluster if that cluster is rendered as a conjunct (see prebase).

Plain vowels

The pronunciation of vowel signs depends on whether they follow an ɑ-class consonant or an ɔ-class consonant. In some cases the alternative may be a diphthong, so compare this also with the items in diphthongsz. Additional variations can arise from context or whether a syllable is open or closed. For more detailed information, click on the characters in the panel, or see vowel_mappings.

As an example of how the same vowel sign is pronounced differently after an ɑ-class and an ɔ-class consonant, check out the pronunciations for 17B7 in the following word.

កិរិយា

The following panel lists basic monophthongs following ɑ-class consonants.

ិ␣ុ␣ឹ␣័␣ៈ␣ា␣់␣៏

The next panel shows vowels following ɔ-class consonants. In several cases the same vowel sign is used, but with a different pronunciation.

ិ␣ី␣ឹ␣ឺ␣ុ␣់␣ូ␣េ␣ោ␣ើ␣ែ

17C8 is a 20th century addition to the Khmer repertoire. It is used as a vowel after consonants that are pronounced as stressed syllables at the end of a word, or preceding an internal juncture in compounds.

17CF is used over just two words: ក៏ ដ៏

For 17D0 see vowel_mod.

Diphthongs

The following panel lists basic diphthongs following ɑ-class consonants. In some cases the alternative may be a diphthong, so compare this also with the items in monophthongs.

ៀ␣ឿ␣េ␣ូ␣ី␣ឺ␣័␣ូវ␣ោ␣ែ␣ើ␣ៃ␣័យ␣ៅ

The next panel shows vowels following ɔ-class consonants. In several cases the same vowel sign is used, but with a different pronunciation.

ា␣ៀ␣ឿ␣ៃ␣័យ␣ៅ␣ូវ␣ួ␣់␣ៈ␣័␣ា◌់␣័␣ា◌់␣ិយ␣័រ

Khmer diphthongs generally end with -j, -w, or ə, but there are a few others that don't. It is noteworthy, also, that not all diphthongs ending with -j or -w use យ or វ.

179A is usually silent in syllable-final position, but the combination 17D0 179A produces the sound ɔə.

ជ័រ

Nikahit and reahmuk

ំ␣ះ

The descendants of the anusvara and the visarga, 17C6 called និគ្គហិត niʔkəhət, and 17C7, called រះមុខ reə̆hmuk, are regarded as vowels in Khmer, even though they represent the sounds -m and -h, respectively.

Used on their own, they can change the inherent vowel, affecting both the pronunciation and the meaning, eg. compare ដម ដំ

Nikahit can also follow vowel signs that would normally produce aː, and u/uː, and change their sound value. The following example shows its effect on the vowel sign 17B6u,643: ពាម ពាំ

The following panel lists rhymes following ɑ-class consonants.

ិះ␣េះ␣ែះ␣ុះ␣ុំ␣ឹះ␣ើះ␣ះ␣ោះ␣ាំ␣ំ␣ាំង

The next panel shows rhymes following ɔ-class consonants. In several cases the same vowel sign is used, but with a different pronunciation.

ិះ␣េះ␣ោះ␣ុះ␣ុំ␣ំ␣ះ␣ាំង␣ាំ

The 2 following sequences are regarded as letters in the Khmer alphabet. They are not encoded separately in Unicode (but they are named sequences).

ាំ␣ុំ

Vowel modifier marks

័␣់

17D0 is used in some Pali and Sanskrit loan words (although alternative spellings exist) and indicates that the syllable has a particular vowel (click on the character in the box for more details).

17CB is always placed above the final consonant, and basically shortens the preceding vowel.

ខាត់

Pre-base vowel signs

េ␣ែ␣ៃ

Three combining marks are displayed to the left of the onset consonant(s).

show composition

កែងដៃ

Relative to the consonants, these combining marks are always typed and stored in the order in which they are pronounced, not the order in which they are displayed. The positioning of the glyph when displayed is managed by the font and rendering software.

In fact, these vowel signs appear before the start of the orthographic syllable. When a syllable onset is a consonant cluster, the vowel sign appears to the left of the initial character in the consonant stack.

show composition

អង្គ្លេស

Circumgraphs

ៀ␣ឿ␣ើ␣ោ␣ៅ

Five vowels are produced by a single combining character with visually separate parts, that appear on different (mostly opposite) sides of the consonant onset.

These are also combining marks that are always stored after the base consonant. The font places the glyphs in the right place relative to the base consonant.

Like the pre-base vowels, the components of a circumgraph vowel are arranged relative to a stack.

show composition

គ្រឿង

None of these circumgraphs decompose during normalisation. See also encoding.

Multipart vowels

Vowels represented by combinations of the above characters (not including decomposed versions of the 2 circumgraphs described below):

ាំ␣ុំ␣ុះ␣េះ␣ោះ␣ា␣ាំង␣ិះ␣ឹះ␣ូវ␣ើះ␣ែះ␣័រ␣ិយ␣័យ

Show which combinations contain a given character:

ា	ា់␣ាំង␣ាំ
ិ	ិយ␣ិះ
ឹ	ឹះ
ុ	ុះ␣ុំ
ូ	ូវ
ើ	ើះ
េ	េះ
ែ	ែះ
ោ	ោះ
ំ	ុំ␣ាំង␣ាំ
ះ	ោះ␣ិះ␣េះ␣ុះ␣ែះ␣ឹះ␣ើះ
់	ា់
័	័យ␣័រ
យ	ិយ␣័យ
ង	ាំង
រ	័រ
វ	ូវ

Show details about vowel glyph positioning.

The following list shows where vowel signs are positioned around a base consonant to produce vowels, and how many instances of that pattern there are. The figure after the + sign represents combinations of vowel sign and niʔkəhət/reə̆hmuk,

3 pre-base, eg. កេ ke
2+1 post-base, eg. កា kā
4+1 superscript, eg. កិ ki
3 subscript, eg. កុ ku
4+1 pre+post-base, eg. កោ ko
1+1 super+post-base, eg. កាំ kām̽
0+1 super+subscript, ie. កុំ kum̽
0+1 sub+post-base, ie. កុះ kuh̽
0+1 pre+post+post-base, ie. កោះ koh̽

At maximum, vowel components can occur concurrently on 2 sides of the base.

Characters that don't appear in the combinations:

ី␣ឺ␣ួ␣ឿ␣ៀ␣ៃ␣ៈ␣ៅ

Standalone vowels

Most of the time, vowels that appear to be standalone are actually pronounced and written after a glottal stop. These use the consonant 17A2 for ɑ-class vowels, or 17A2 17CA for ɔ-class vowels. They are usually followed by a vowel sign, but when used alone they represent the sound of the inherent vowel, eg.

អូ

អ៊ូ

ចង្អូរ

The combination of 17A2 and a vowel sign can also occur as a subscript below a consonant onset or final consonant, eg.

ក្អាត់

ចង្អៀត

Independent vowels

Khmer also has independent vowel letters that can be used to represent some of these sounds, but unlike most South Asian scripts, there are fewer independent vowels than vowel sounds, and some do not have direct correspondences with a simple vowel sign. For example, 17AA corresponds phonetically to the multipart vowel 17A2 17BC 179C. (See also vocalics.)

ឥ␣ឦ␣ឪ␣ឧ␣ឩ␣ឯ␣ឰ␣ឱ␣ឳ␣ឲ

Whether a vowel sound is represented using an independent vowel letter or the glottal consonant plus vowel sign varies from word to word. In Cambodian orthography the two are not interchangeable. The independent vowel letters appear in relatively few words, but some of those words are quite common, eg. ឪពុក ឲ្យ ឮ

Other characters

The Unicode Khmer block contains 3 more independent vowels that are either obsolete or strongly deprecated.

ឨ

The Unicode Standard regards the following 2 characters as errors in the encoding.

ឣ␣ឤ

Vowel length

Vowel length is distinctive in Khmer. Short and long vowels are written using different vowel characters. For example, compare the long and short i vowel signs in the following word.

ហ្វ៊ីស៉ិក

Silent vowels & consonants

Inherent vowels are not pronounced after syllable final consonants.

Vowels are not pronounced between stacked consonants. The first character in the list below, 17D2, is used to create those consonant stacks. It is never visible when part of a cluster. (When rendered alone or without a following consonant, fonts do however apply a visible form.) See clusters.

Khmer also has other diacritics that silence vowels or parts of the text.

្␣៍␣៌␣៑␣៝

The following two diacritics are used to silence written characters.

17CD is used over a consonant, particularly in loan words, to silence it and any attached vowels or subscripts.

សប្ដាហ៍

រេហ៍ពល

កេរ្តិ៍

17CC is not very common and word-medially may produce rə before the consonant it sits on. When it appears word-finally, it may silence the final consonant (and may also affect vowel sounds).

បរិបូណ៌

17D1, the sanskrit virama, is sometimes used in Sanskrit words to indicate that a final consonant has no vowel sound.

អាត្មន៑

17DD, on the other hand, is a rarely used sign that indicates that a final consonant retains its inherent vowel sound.

(Check the detailed information for each of the above marks, since this section only looks at the use for silencing sounds.)

Vowel sounds mapped to characters

This section maps Cambodian vowel sounds to common graphemes in the Khmer orthography.

Sounds in the left-most column are produced after an ɑ-class consonant; the middle column vowels are produced after an ɔ-class consonant; and the right-hand column contains independent vowels. The dotted circle indicates the location of the consonant relative to the vowel sign; if there are 2 circles, the vowel is used only in closed syllables.

Click on a grapheme to find other mentions on this page (links appear at the bottom of the page). Click on the character name to see examples and for detailed descriptions of the character(s) shown.

Plain vowels

After ɑ-register consonants

After ɔ-register consonants

Independent vowels

17B7 Followed by a glottal stop in stressed syllables, but not in unstressed.

និទាន
លទ្ធិ

iː

17B8

ពីរ

17B7 1799

ឥន្ត្រិយ

17B9

ទឹក

17B7 except before 1799.

ជិត

17C1 before palatals.

ពេញ

17A5

ឥន្ទុ

ɨː

17BA

គឺ

17BB Followed by a glottal stop in stressed syllables, but not in stressed.

វិទ្យុ
គុលិកា

17BB

គុណ

17CB after an inherent, series 2 vowel and before a labial final.

ទប់

17A7

ឧបម៉ា

uː

17BC

គូ

17A9

ឩន

17B7 Followed by a glottal stop in stressed syllables, but not in unstressed.

មតិ
កិរិយា

eː

17C1

គេ

17BB Followed by a glottal stop in stressed syllables, but not in unstressed.

វត្តុ
កុមារ

17BB

ឧកញ៉ា

17A7

ឧកញ៉ា

oː

17C4

គោ

17B7

ចិត្ត

17B9

ដឹក

17C1 before palatals.

ម៉េច

17A5

ឥត

əː

17BE

ឈើ

ɛː

17C2

គែ

ɔː

Inherent vowel

គ

17D0

ស័ក

17B6 25CC 17CB

កាត់

aː

17B6

តា

17CB after an inherent, series 1 vowel.

កត់

ɑː

Inherent vowel

ក

Diphthongs and other combinations

After ɑ-register consonants

After ɔ-register consonants

iə

17B6

ជា

17C0

តៀប

17C0

ទៀប

17B7 17C7

ជិះ

17C1 17C7

នេះ

ɨə

17BF

តឿ

17BF

ជឿ

ɨj

17D0 1799

ជ័យ

17C3

ព្រៃ

ɨw

17BC 179C

នូវ

17C5

ទៅ

uə

17BD

កួរ

17BD

គួរ

uə̆

17CB after an inherent, series 2 vowel and before a non-labial final.

យល់

uə̆h

17C4 17C7

គោះ

17BB 17C7

ពុះ

17BB 17C6

ទុំ

17C6

ទំ

eə̆

17D0 before velar finals.

ល័ខ

17B6 25CC 17CB before velar finals.

ទាក់

17C1

កេរ្តិ៍

17B7 17C7

តិះដៀល

17C1 17C7

សេះ

17C2 17C7

កែះ

eə̆h

17C7

ទះ

eə̆ŋ

17B6 17C6 1784

ទាំង

17BC

កូរ

17A9

ឩដ្ឋ

oə̆

17D0 before non-velar finals.

ទ័ព

17B6 25CC 17CB before non-velar finals.

គាត់

oə̆m

17B6 17C6.

ជាំ

17BB 17C7.

ចុះ

17BB 17C6.

ដុំ

əɨ

17BA

ដឺ

əj

17B8

បី

17B7 1799

ចេតិយ

17A5

ឥឡូវ

17A6

ឦសាន

əw

17BC 179C

ត្រូវ

17AA

ឪពុក

əh

17B9 17C7

ឆ្កឹះ

17BE 17C7

ចង្កើះ (normally spelled ចង្កឹះ cŋ͓kɨh̽).

ɔə

17D0 179A.

ជ័រ

17C2

កែ

17AF

ឯ

aə

17BE

បើ

17C4

កោរ

17A7

ឧបាសក

17B1

ឱប

17B2

ឲ្យ

17D0 1799

សម័យ

17C3

ប្រៃ

17B0

ឰរាវ័ណ

17C5

តៅ

17B3

ឳទក

17C4 17C7

កោះ

17C7

តះ

17B6 17C6

ចាំ

ɑm

17C6

ចំ

ɑŋ

17B6 17C6 1784

តាំង

Vocalics

Khmer represents vocalics only as independent vowel letters.

ឫ␣ឬ␣ឭ␣ឮ

The following words shown examples of them in use.

ឫស

ឬស្សី

រំឭក

ស្ដាប់ឮ

Consonants

Consonant summary table

The following table summarises the main consonant to character assigments.

Consonants of the ɑ-class register appear on the left, ɔ-class on the right.

	ɑ-class register	ɔ-class register
Stops	ប៉␣ត␣ច␣ក␣ហ្គ␣អ	ព␣ទ␣ជ␣គ␣ហ្គ៊
	ប␣ដ	ឌ
	ផ␣ថ␣ឋ␣ខ␣ឆ	ភ␣ធ␣ឍ␣ឃ␣ឈ
Frictives	ហ្វ␣ស␣ហ្ស␣ហ	ហ្វ៊␣វ␣ហ្ស៊
Nasals	ហ្ម␣ណ␣ហ្ន	ម␣ន␣ញ␣ង
Other	ហ្ល	រ␣ឡ␣ល␣យ
Followed by coeng	ប␣ផ␣ត␣ដ␣ថ␣ឋ␣ក␣ខ	ព␣ភ␣ទ␣ឌ␣ធ␣ឍ␣គ␣ឃ
Finals	ព␣ប␣ផ␣ភ␣ទ␣ដ␣ឌ␣ថ␣ឋ␣ធ␣ឍ␣ក␣គ␣ខ␣ឃ
	ច␣ជ
	ម␣ណ␣ន␣ញ␣ង
	វ␣រ␣ល␣យ

For additional details see vowel_mappings.

Basic consonants

This shows consonants in use in modern Khmer, although some are not widely used. Whereas the table just above takes you from sounds to letters, the following simply lists the basic consonant letters.

Khmer is not tonal, but each consonant character belongs to one of two classes (see consonant_registers). The class of a consonant determines the vowel sound in a syllable, however this can also be changed (see register_change).

Some letters have different sounds when they appear in the syllable onset and the syllable coda. Some also have different pronunciations when they appear at the beginning of a consonant cluster in the onset (see onsets).

Where pronunciation differs, forms such as p- indicate the sound at the start of a consonant cluster, and -p at the end of a syllable.

ɑ-class

ព␣ភ␣ទ␣ឌ␣ធ␣ឍ␣គ␣ឃ␣ជ␣ឈ␣ម␣ន␣ញ␣ង␣វ␣រ␣ឡ␣ល␣យ

ɔ-class

ប␣ផ␣ត␣ដ␣ថ␣ឋ␣ក␣ខ␣អ␣ច␣ឆ␣ស␣ហ␣ណ

The following 3 consonants are obsolete, and used only for Pali/Sanskrit transliteration.

ឝ␣ឞ␣ៜ

Additional consonants

Special combinations are used to represent non-native sounds in loan words, especially from French and Thai. These include the following, most of which involve a stack beginning with ហ.

ប៉␣ហ្គ␣ហ្គ៊␣ហ្វ␣ហ្វ៊␣ហ្ស␣ហ្ស៊

Changing consonant registers

There are not enough individual Khmer consonant letters to be able to assign a unique character for each ɑ-class and ɔ-class register. Khmer extends the number of letters as follows to close this gap.

Two diacritics, 17C9 and 17CA, are used to change the class of a consonant. These are particularly useful when a given sound has only one character associated with it, such as the letters ម, យ and ស etc.

៉␣៊

These diacritics appear above the base consonant or stack by default, but if another combining mark (such as a vowel sign) appears above the base (for certain consonants) the register shifter may move below the base and looks identical to 17BB (see consonant_shift_posn).

Regardless of displayed position, each of these diacritics should be typed and stored immediately after the base character, unless a ZWNJ intervenes.u,647

A small number of ɔ-class consonants are transformed into ɑ-class consonants by preceding them with 17A0, rather than using the above diacritics. They include the following.

ហ្ម␣ហ្ន␣ហ្ល

Onsets

Word-initial consonant clusters are relatively common in Khmer. These include sounds commonly referred to as medials, such as -r and -l, but also a wider assortment of consonant clusters. For example:

ក្ដារ

ឆ្កែ

ធ្មេញ

ផ្សែង

The consonant clusters are written as stacks, using the coeng. See clusters.

In addition, Khmer creates syllable-initial stacks using 17A0 followed by another consonant to create sounds from other languages, or to change the register for the subjoined consonant. These combinations produce a single consonant sound, unlike the former examples, but they are handled using the normal stacking mechanism. See extendedC.

Finals

Not all Khmer consonants can appear in syllable-final position. The most common syllable codas include the following:

ប␣ត␣ក␣ម␣ន␣ញ␣ង␣ល

The pronunciation of the consonant in final position may differ from it's normal pronunciation, but it is not followed by a vowel sound.

Because ordinary letters are used in word-final position, and there are no indicators for syllable or word boundaries, it is difficult to parse Khmer or automatically generate pronunciation. For example, the following sequence could equally represent two syllables kɑːkɑː with inherent vowels, or one syllable with a final -k, pronounced kɑːʔ. កក

Two final consonant sounds -m and -h can also be produced using combining characters. See nikahit_reahmuk for details.

Consonant clusters

In Khmer, word-internal clusters are very common at the beginning of a word, but clusters also occur medially in multisyllable words, and occasionally at the end of a word.

The absence of a vowel sound between two or more consonants is visually indicated by stacked consonants (only), where the non-initial consonant appears below the initial, typically with a different shape from normal.

In Unicode, the stacking behaviour is achieved by adding 17D2 between the consonants. This character has no visual representation in normal Khmer text, however most fonts render it as a small cross when used alone or without a following consonant. It is never visible when used in consonant clusters.

Word boundaries. Clusters do not span word boundaries. Consonant clusters formed by the end of one word and the beginning of the next do not lead to stacking in Khmer.

Stacking

្

Subscript consonant forms are called ជើងអក្សរ (or 'coeng', pronounced cəːŋ).

Cambodians see these subscripts as distinct letter forms, but, unlike Tibetan, they are produced in Unicode by inserting 17D2 before the consonant that will become a subscript. This character, which has no visual form in Cambodian, is called the coeng in Unicode, although it should rightly be called the coeng generator.

All the shapes are simplified and reduced in size compared to the non-subscript form. Many have significantly different shapes.

This list shows consonants in their normal and subjoined forms

Class ɑː consonants

ផ្ផ␣ប្ប␣ត្ត␣ថ្ថ␣ឋ្ឋ␣ដ្ដ␣ក្ក␣ខ្ខ␣អ្អ␣ច្ច␣ឆ្ឆ␣ស្ស␣ហ្ហ␣ឡ្ឡ

Class ɔː consonants

ព្ព␣ភ្ភ␣ទ្ទ␣ធ្ធ␣ឍ្ឍ␣ឌ្ឌ␣គ្គ␣ឃ្ឃ␣ជ្ជ␣ឈ្ឈ␣វ្វ␣ម្ម␣ន្ន␣ណ្ណ␣ញ្ញ␣ង្ង␣រ្រ␣ល្ល␣យ្យ

179A produces a subjoined form that wraps to the left and under the preceding consonant. Several others wrap below and to the right of the consonant. 17A1 doesn't normally appear in subscript form.

Some subscripts change the sound of the preceding consonant.

Stacks commonly occur in multisyllabic words. A medial cluster will typically contain a final consonant for the first syllable and the initial consonant of the next syllable.

កម្មករ

Some clusters involve two subscripts. These are, with 3 exceptions, composed of a final nasal, followed by a stop and r.

កន្ត្រៃ

កញ្ជ្រេង

The 3 exceptions are loan words.

អង្គ្លេស

សងស្ក្រិត

សាស្ត្រាចារ្យ

Subscript consonants that appear at the end of a word, are silent.

ពេទ្យ

រដ្ឋ

Stacks and registers

Where the two consonants involved in the cluster are in different classes or registers, the pronunciation of any following vowel is normally determined by the register of the subscript consonant. For the following exceptions, however, the vowel pronunciation is determined by the register of the first consonant (all ɔ-class):

ង␣ញ␣ន␣ម␣យ␣រ␣ល␣វ

Combining characters & stacks

Most vowels that are pronounced after a consonant stack are displayed as if they were attached to the consonant at the top of the stack (including pre-base vowel signs and circumgraphs).

Click on the examples to see the underlying sequence more clearly.

ក្លិន

ឆ្វេង

ភ្លៀង

This can also lead to ligation between the top consonant in the stack and a vowel sign, unless the subjoined consonant is right-spacing.

ក្ដារ

ក្រាក់

ក្បាល

The exceptions are the vowel signs that appear below the consonant; these appear below the last subjoined form, unless the subjoined form is left-spacing.

ខ្ពុរ

ត្រុំ

Other diacritics are treated in a similar fashion. This can lead to ambiguity if a diacritic could modify either consonant in a stack.

Subscript consonants after vowels

It is rare but possible to find subscripts used after independent vowels. One common word spelled this way is ឲ្យ

It is also possible to find subscript forms of independent vowels. Four of these are named sequences in Unicode.

Consonant sounds to characters

This section maps Cambodian consonant sounds to common graphemes in the Khmer orthography.

When a row has two columns, the left is an ɑ-register consonant (class 1), and the right is an ɔ-register consonant (class 2).
A consonant followed by a coeng indicates that this different sound is produced when it is followed by a subjoined consonant.

Click on the character name to see examples and for detailed descriptions of the character(s) shown. Sounds listed as 'infrequent' are allophones, or sounds used for foreign words, etc.

Onsets

ɑ-register consonants

ɔ-register consonants

1796 17C9

ព៉ី

1796

ពី

1794 in some words by convention

បច្ច័យ

1794 17C9

ប៉ា

1794 17D2

ប្រយ័ត្ន

1795 17D2

ផ្សារ

1797 17D2

ភ្នែក

pʰ

1795

ផាយ

1797

ភាយ

1794

ប្រុត

1794 17CA

ប៊ុត

178F

តា

1791

ទា

178B 17D2

1792 17D2

ធ្មេញ

tʰ

1790

ថូ

178B Only used in a few words of Pali or Sanskrit origin.

ឋាន

1792

ធូរ

178D Only used in a few words of Pali or Sanskrit origin.

ឍាល

178A

ដុន

178C Rare and only used in a few words of Pali or Sanskrit origin.

ឌុន

178F at the beginning of two-syllable words where the first syllable ends with final nasal.

តង្វាយ

1785

ចា

1787

ជា

cʰ

1786

ឆោង

1788

ឈ្លើង

1780

ក

1782

គ

1781 17D2

ខ្ពុរ

1783 17D2

ឃត់

kʰ

1781

ខត់

1783

ឃត់

1780 17D2 when followed by a subscript 1798, 1793, or 179B.

ក្មេង

1782 17D2 when followed by a subscript 1798, or 1793.

គ្នា

17A0 17D2 1782 for loan words.

ហ្គាស

17A0 17D2 1782 17CA for loan words.

ហ្គ៊ារ

17A2

អង្កាល់

17A2 17CA

អ៊ី

17A0 17D2 179C

ហ្វឹក

17A0 17D2 179C 17CA

ហ្វ៊ីស៉ិក

179C 17C9

វ៉ៃ

17A0 17D2 179C

ហ្វូង

179C

វៃ

179F

សី

179F 17CA

ស៊ី

ʒ z

17A0 17D2 179F

ភីហ្សា

17A0 17D2 179F 17CA

ហ្ស៊ីប

17A0

ហាង

17A0 17CA

ហ៊ាន

1798 17C9

ម៉ែ

17A0 17D2 1798

ហ្មត់

1798

មែ

178E

ណាយ

17A0 17D2 1793

ហ្នឹង

1793

នាយ

1789 17C9

ញ៉ាំ

1789

ញាំ

1784 17C9

ង៉ាវ

1784

ងាវ

179A 17C9

រ៉ូង

179A

17A1

ឡេង

17A0 17D2 179B in some words.

ហ្លួង

179B

លាង

1799 17C9

យ៉ាង

1799

យាង

Vocalics

rɨ

17AB

ឫស

rɨː

17AC

ឬស្សី

lɨ

17AD

រំឭក

lɨː

17AE

ឮ

Finals

-p

1796

ភាព

1797

លោភ

1794

រៀប

1795 Not common.

-t

178F

កាត់

1791

បាទ

178A

ប្រាកដ

178B

បាឋ

178A 17D2 178B

ឥដ្ឋ

178C

គ្រុឌ

1790

ប្រមាថ

1792

អាវុធ

178D

អាសាឍ

-c

1785

តូច

1787

រាជ

-k

1780

ជីក

1782

រោគ

1781

មុខ

1783 Not common.

មេឃ

-ʔ

All of the following occur after one of the following vowels: a, aː, ɑ, ɑː, eə̆, uə̆, iə, ɨə, uə.

1780

នាគ

1782

នាគ

1781

ពិសាខ

1783

មាឃ

-h

179F

ចាស់

17C7 This represents -ah after a 1st class consonant, and -eə̆h after a 2nd class consonant.

ទះ

-m

1798

តាម

17BB 17C6

ដុំ

17C6

ចំ

17B6 17C6

ចាំ

-n

1793

មាន

178E

បូរាណ

-ɲ

1789

ទាញ

-ŋ

1784

ដឹង

1789 after iː.

រីញ

-w

179C when it appears in the syllable coda as a final glide.

អាវ

17C5

ហៅ

-l

179B

កាល

-j

1799

បាយ

17C3

ព្រៃ

Encoding choices

In some fonts, two circumgraphs look the same whether they are written as a single character, or as two.

Recommended	Not recommended
17BE	17C1 17B8
17C4	17C1 17B6

For Khmer, single and multiple code point realisations do not normalise to be the same in NFC or NFD, so you are creating different content by using one approach or the other. This may affect various operations on the text, and it is therefore better to stick with one representation. The Unicode Standard surprisingly makes no comment on this, although it does for other scripts, where it encourages use of the precomposed, single code point.

Also, some fonts may not display the decomposed sequences correctly.

Inherent vowel letters

The invisible characters 17B4 and 17B5 were originally intended to represent a phonetic difference not expressed by the spelling, so as to assist in phonetic sorting, however, the Unicode Standard considers them insufficient for that purpose and errors in the encoding, and they should not be used.u,677

Codepoint sequences

Components of an orthographic syllable should be composed in the following order:

base consonant or independent vowel
rɔɓaːt
museʔkətoə̯n or trəisaɓ (register shifters)
subscript (consonant or independent vowel)
vowel sign
zero-width joiner or non-joiner
any other mark

This fixed ordering makes it easier to search for and collate text. For more details, see this SIL document.sil

Numbers, dates, currency, etc.

Khmer has its own set of decimal digits, although western digits are also used sometimes.

០␣១␣២␣៣␣៤␣៥␣៦␣៧␣៨␣៩

The thousands separator is ., and decimal separator is ,.

Ranges and dates use the ASCII hyphen.ws,#Spacing_and_punctuation

Currency

៛

The symbol 17DB (សញ្ញារៀល sɲ͓ɲāṟiᵊḻ saɲ ɲaː riəl) is placed after the amount, eg. ៣.០០០ ៛ ɓej poan riəl 3,000 riel. Sometimes 179A is used instead.

Other

The Unicode Khmer block contains a set of numeric symbols for divination lore.

៰␣៱␣៲␣៳␣៴␣៵␣៶␣៷␣៸␣៹

Use of 17D3 is discouraged in favor of the complete set of lunar date symbols.

The Khmer Symbols block is entirely composed of Lunar date symbols.

᧠␣᧡␣᧢␣᧣␣᧤␣᧥␣᧦␣᧧␣᧨␣᧩␣᧪␣᧫␣᧬␣᧭␣᧮␣᧯␣᧰␣᧱␣᧲␣᧳␣᧴␣᧵␣᧶␣᧷␣᧸␣᧹␣᧺␣᧻␣᧼␣᧽␣᧾␣᧿

Text direction

Khmer text runs left to right in horizontal lines.

Show default bidi_class properties for characters in the Khmer orthography described here.

Glyph shaping & positioning

You can experiment with examples using the Khmer character app.

Font styles

Modern Khmer has several distinct styles of font, each of which is used for different purposes.

Most modern typefaces are set in an upright style (called អក្សរឈរ ʔk͓sṟc̱ʰṟ ʔɑːksɑː cʰɔː or អក្សរត្រង់ ʔk͓sṟt͓ṟŋ˘ ʔɑːksɑː trɑŋ).ws,#Styles This is the style used for this page.

មនុស្សទាំងអស់ កើតមកមានសេរីភាព និងសមភាព — Text in an âksâr chôr font style.

A slanted style (អក្សរជ្រៀង ʔk͓sṟc̱͓ṟiᵊŋ ʔɑːksɑː criəŋ) is sometimes used for whole documents or novels. The oblique styling has no affect on the semantics of the text.ws,#Styles

The round style (អក្សរមូល ʔk͓sṟm̱ūḻ ʔɑːksɑː muːl) has heavier, more rounded letter shapes, and includes more ligated forms. It is commonly used for titles and headings in Cambodian documents, books, or currency, as well as on shop signs or banners. It may also be used to emphasise important names or nouns.ws,#Styles The regular font weight looks like bolded text in comparison to the upright font style.

Another style (អក្សរខម ʔk͓sṟkʰm̱ ʔɑːksɑː kʰɑːm), characterized by sharper serifs and angles and retention of some antique characteristics, is used for yantra text in Cambodia as well as in Thailand.ws,#Styles

An example of a page that mixes upright (regular and bold) with mul font styles. (Click on the image to see bigger.)

Context-based shaping & positioning

This section mentions a handful of exceptions to the general rule that there is very little in the way of interaction between characters other than where the subscript shapes are used after the coeng generator.

Subjoined consonants can be quite different shapes from those of the corresponding base consonant, and those shapes can be seen in clusters. However, some additional reshaping of glyphs is needed to cope with stacking of characters. Compare for example the length of the final element fig_long_subjoined_yo.

ង្យ ង្ខ្យ — The subjoined form of 1799 is lengthened when it is the second subjoined consonant.

Glyph order

Although all combining characters follow the base in memory, the visual order of syllable components may not follow a linear progression from left to right. In the following example the order in which the glyphs are pronounced is far left, far right, down, left, left: កន្ត្រៃ In the word ច្រៀង the spoken order of the separate visible parts, numbered left to right, is 3,2, 1+4, 5, Some vowel signs span two or three sides of the base consonant or cluster.

Joining forms for AA

Some small joining features occur in relation to 17B6 and similarly shaped vowels. Unicode provides the following list of common forms:

ក + ា = កា
ប + ា = បា (avoids confusion with ហ )
ប + ៅ = បៅ
្ស + ា = ្សា

Register-shifter position

The function of the register-shifter marks is described in register_change.

When 17C9 museʔkətoə̯n or 17CA trəisaɓ appears with a vowel sign above the consonant, the ក្បៀសក្រោម kɓiəhkraom form may be used. This looks exactly like 17BB. See fig_posn_muse.

ញ៉ាំ — Alternative positions and shapes of MUUSIKATOAN.

ម៉ឺន — Alternative positions and shapes of MUUSIKATOAN.

show composition

យ៉ាង

show composition

ម៉ឺន

show composition

ញ៉ាំ

fig_posn_triisap provides some examples of TRIISAP.

អ៊ី — Alternative positions and shapes of TRIISAP.

show composition

អ៊ូ

show composition

អ៊ី

The Unicode Standardu,647 gives the impression that both of these diacritics are moved below the consonant any time a vowel appears over that consonant. However, in reality only certain consonants cause this behaviour. The behaviour varies a little by font, but in general the MUUSIKATOAN diacritic is lowered for the following letters:

ប␣វ␣ម␣ន␣ញ␣ង␣រ␣ល␣យ

TRIISAP is lowered for these characters.

ស␣ហ␣អ

For more details, see this SIL document.sil

If needed, this behaviour can be modified using 200C, if the font recognises it, to prevent the low form appearing. The ZWNJ must be typed and stored between the base consonant and the register-shifter. See fig_zwnj_triisap for an example using ប្រតឺងអ‌៊ឹះ.

ប្រតឺងអ៊ឹះ — TRIISAP rendered above the consonant by using ZWNJ immediately before it (left), when it would otherwise be moved below the consonant (right).

show composition

ប្រតឺងអ‌៊ឹះ

Observation: Textarea entry fields on the Mac don't seem to recognise the ZWNJ character (mentioned below) and incorrectly display the combining characters that follow it. The text looks ok if the browser displays the sequence as part of the HTML.

NYO with subscripts

Another common feature is that ញ drops the swash below the baseline when followed by a subscript consonant.

បញ្ជី — The normal, full shape of NYO (left), and the reduced shape when a subjoined consonant follows (right).

show composition

ឃើញ

show composition

បញ្ជី

Also, when it appears as a subscript under itself it uses a special full form subscript (see fig_nyo_subj).

កញ្ញា — The normal subjoined shape of NYO (left), and the special shape when gemination causes it to be subjoined below itself (right).

show composition

ប្រាជ្ញា

show composition

កញ្ញា

Vowel ligatures

In the âksâr mul style, some vowel signs ligate with the consonant characters to which they are applied. See the word វិទូ in fig_vowel_ligatures.

show composition

វិទូ

Observation: This behaviour is font dependent. For example, the Khmer Mool font (used for the figure), and Khmer OS Muol produce the ligation, but the Khmer Ratanakiri font does not.

To prevent a ligature forming, use 200C (ZWNJ) between the consonant and the vowel. To cause a ligature to form when there isn't one, if the font has the appropriate rules, use 200D (ZWJ) instead.u,647

Managing glyph shaping

Content authors can use 200C and 200D to change the position of register shifters (see consonant_shift_posn), and to manage ligatures in mul fonts (see vowel_ligatures).

Typographic units

Word boundaries

Khmer words are not separated by spaces, nevertheless Khmer should be wrapped at word boundaries.

Sometimes 200B may be used to indicate appropriate break-points.

Some other languages that use the Khmer script, such as Krung and Tampuan, do separate words with narrow spaces such as 2006, and separate phrases with a wider space such as 2003.sil,5

Names

- (called សហសញ្ញា sɑːhɑː sɑːɲɲiə) is used between the parts of a person's name. Typically the family name (written first) and following names, but often all names for Chinese Cambodians, eg.

ញ៉ុក-ថែម ɲok tʰaem

លី-ធាម-តេង liː tʰiəm teiŋ

Graphemes

This section is still undergoing research and development.

Grapheme clusters alone are not sufficient to represent typographic units in Khmer. Conjunct stacks are common and must not be split apart by edit operations that visually change the text (such as letter-spacing, first-letter highlighting, and in-word line breaking). For those operations one needs to segment the text using orthographic syllables, which string grapheme clusters together with an invisible stack generator. This character is never visible, so Khmer doesn't have the problems of ambiguity that affect various other Brahmi-derived scripts.

The Khmer stack former (coeng) is 17D2, which has an Indic Syllabic Category of Invisible_Stacker.

Grapheme clusters

Base ZW(N)J? Combining_mark*

This fixed ordering makes it easier to search for and collate text. For more details, see this SIL document.sil

Combining marks may include zero or more of the following types of character.

Consonant shifters [2] (see register_change) Only one per grapheme cluster, typed and stored immediately after the base consonant.
Dependent vowels [19] (see combiningV) Always a single code point, even for circumgraphs (see circumgraphs).
Final consonant marks [2] (see nikahit_reahmuk) One of 2 possible combining marks, at the end of a grapheme cluster sequence. (Cambodians consider these to be vowels.)
Coeng generator [1] (see subscript_consonants) Normally occurs immediately after a consonant at the beginning of a cluster. It sometimes also appears after an independent vowel.
Other diacritics [6] (see vowel_mod, novowel, and emphasis) Normally occurs at the end of a syllable.

In some cases, a ZWNJ is inserted between a consonant and a consonant shifter in order to specify special shaping rules for the shifter (see consonant_shift_posn).

To prevent or encourage the formation of ligatures (especially for mul fonts) a ZWNJ or ZWJ can be inserted between a consonant and following dependent vowel (see vowel_ligatures).

The following examples show a variety of grapheme clusters:

Click on the text version of these words to see more detail about the composition.

	បរិបូណ៌
	ប៉ាន
	នុ៎ះន៎
	ចង្អូរ
	កញ្ជ្រេង
	ប្រតឺងអ‌៊ឹះ

The last syllable of the last item in the list contains a ZWNJ (to keep the register shifter above the base).

Note how grapheme clusters segment the parts of a conjunct after the virama. This is not always desirable (see orthographicS just below).

Larger typographic units

(Consonant Coeng)* Grapheme_cluster

Khmer commonly stacks glyphs, to form conjuncts (see clusters). These conjuncts represent consonant clusters or gemination. The stacking does not occur across word boundaries; only within words.

Grapheme clusters terminate after a sequence of marks that includes a coeng indicator code point, but editorial operations that change the visual appearance of the text, such as letter-spacing, first-letter highlighting, line-breaking, and justification, should never split stacked forms apart. For this reason, an alternative way of segmenting graphemes is needed. This may not apply, however, for some other operations such as cursor movement or backwards delete.

Where stacks appear, a typographic unit contains multiple grapheme clusters. The non-final grapheme clusters all end with 17D2, which is never visible, and the final grapheme cluster begins with a consonant.

The following are examples. Some of these examples were shown in the previous section: here the stack is treated as a single typographic unit.

Click on the text version of these words to see more detail about the composition.

	ចង្អូរ
	កញ្ជ្រេង
	អភិវឌ្ឍ
	ភ្លៀង

Browser behaviour

Test in your browser. The words test units that equate to grapheme clusters only, and others that include conjuncts. First, the text is displayed in a contenteditable paragraph, then in a textarea. Results are reported for Gecko (Firefox), Blink (Chrome), and WebKit (Safari) on a Mac.

បរិបូណ៌ប៉ានចង្អូរកញ្ជ្រេងឲ្យប្រតឺងអ‌៊ឹះ

Cursor movement. Move the cursor through the text.
Gecko and Blink step through the text using grapheme clusters. It takes 2 or more steps (depending on the number of GCs) to get through the stacks, one grapheme cluster at a time. In some cases the cursor may look as if it is not moving. WebKit steps through all words using the orthographic syllables as described here (ie. they step over a stack and all associated combining characters in one jump), except that WebKit treats the ZWNJ as the start of a new grapheme cluster, requiring an extra jump to get past it.

Selection. Place the cursor next to a character and hold down shift while pressing an arrow key.
The behaviour is the same as for cursor movement.

Deletion. Forward deletion works in the same way as cursor movement. The backspace key deletes code point by code point, for all browsers.

Line-break. See this test. The CSS sets the value of the line-break property to anywhere. Change the size of the box to slowly move the line break point.
Gecko and Blink set break opportunities based on orthographic syllables. WebKit wraps on grapheme cluster boundaries, but gets rather confused by the stacks, typically wrapping half the stack plus one adjoining (non stack) character together.

Punctuation & inline features

Phrase & section boundaries

៖␣។␣?␣!␣៎␣៕␣៙␣៚

Khmer uses mostly native punctuation marks, but also a couple of ASCII punctuation.

phrase	U+0020 SPACE ៖
sentence	។ ? ! 17CE
section	៕
text	៙ ៚

Space. Although Khmer words are not separated by spaces, the space (ឃ្លា kliə) is used, and is regarded as punctuation, similar to the comma. Huffman lists the following uses:

between clauses within a sentence
between sentences in a cohesive group of sentences
after preposed adverbial phrases, such as 'usually', 'today', 'in that town', etc.
before and after proper names
before and after numbers
before and after the symbols ។ and ៗ and the terms ។ល។ and ។ប។
between coordinate words in lists

Huffman gives the following example to show the use of the space:

ថ្ងៃនេះ ខ្ញុំទៅផ្សារ ទិញក្រច អង្ករ ហើយនឹងអីវ៉ាន់ផ្សេង ៗ
tŋajnih kɲomtɨwpsaː tiɲkrouc ʔɑŋkɑː haəjnɨŋʔəjʋanpseiŋ pseiŋ
Today ( ) I'm going to the market ( ) to buy oranges ( ) rice ( ) and various things.

As mentioned in word, some other languages use narrow spaces to separate words, and wide spaces, such as the EM SPACE, to separate phrases

Phrasal punctuation marks. Khmer also uses ។ to mark the end of sentences, although a series of sentences on a related topic tend to be separated by space instead.

៖ is used in much the same way as a western colon.

Question & exclamation marks. Khmer uses Western punctuation marks, eg. ហេត៊អ្វី? haetʰ aʋəi, and កុំ! kom.

Very rarely, the combining character 17CE can be used over the final consonant of a word like an exclamation mark, to convey excited emphasis, eg. ណែ៎ nɛː Hey! នុ៎ះន៎ nuhnɔː Over there!

Section boundaries. ៕ can be used to close a chapter, or an entire text.

Text start and end. Poetic and religious texts typically start with ៙ and end with ៚.

Bracketed text

(␣)

Khmer commonly uses ASCII parentheses to insert parenthetical information into text.

	start	end
standard	(	)

Quotations & citations

“␣”␣‘␣’

Khmer texts typically use quotation marks around quotations. Of course, due to keyboard design, quotations may also be surrounded by ASCII double and single quote marks.

	start	end
initial	“	”
nested	‘	’

According to CLDR, the default quote marks for Khmer should be, reading right to left, “...”. When an additional quote is embedded within the first, the quote marks should be ‘...’.

Emphasis

៎

17CE is very rare, but is used over the final consonant of a word like an exclamation mark, to convey excited emphasis, eg. ណែ៎ នុ៎ះន៎

Emphasis may also be conveyed by repeating words (see repetition).

Abbreviation, ellipsis & repetition

Ellipsis

The following word (pronounced laʔ) is used as the equivalent of 'etc.' ។ល។

A character exists that represents that sequence, ៘, but the Unicode Standard deprecates it, and recommends the use of the three separate characters instead.u

៘

Other spellings for et cetera also exist. These include:

។បេ។
–បេ–
–ល–

Repetition

ៗ

It is common to repeat words or sometimes phrases in Khmer, particularly to provide emphasis. ៗ (called លេខទោ leːktoː) can be used for this, eg. ខ្លាំង ៗ klaŋklaŋ very strong គាត់មានផ្ទះថ្មី ៗ kaːtʰ miən pʰteə̯h tʰməitʰməi he has a brand new house

Sometimes this sign repeats a phrase rather than a word, eg. បន្តិចម្ដង ៗ ɓɑntecmɗɑːŋ ɓɑntecmɗɑːŋ little by little

It is also occasionally used to repeat the word at the end of a sentence for the beginning of a new sentenceh, eg. ខ្ញុំទៅផ្ទះខ្ញុំ ៗ នៅជិតផ្សារ kɲomtɨwpteə̆hkɲom pteə̆hkɲom nɨwcɨtpsaː

The sign is usually separated from the text by a space.

Line & paragraph layout

Line breaking & hyphenation

Although Khmer doesn't use spaces or dividers between words, the expectation is that line-breaks occur at word boundaries.

There are three basic types of Khmer word, shown in the figures that follow. The first two types cannot be broken, but the third type can be broken where indicated by the vertical lines.@Hong (Github),https://github.com/w3c/sealreq/issues/4#issuecomment-384981313

show composition

កម្ម

ជាតិ

វិទ្យាល័យ

show composition

កម្មករ

អន្តរជាតិ

មហវិទ្យាល័យ

show composition

កម្មផល

សកលវិទ្យាល័យ

ជាតិសាសន៍

Text is not broken at sub-word syllable boundaries. In fact, this is particularly difficult to do algorithmically in Khmer, because syllable-final consonants are indistinguishable from consonants with an inherent vowel that constitute a new syllable. Some kind of morphological analysis is needed.

Zero-width space & word-joiner

Because Khmer doesn't separate words, applications typically look up word boundaries in a dictionary, however, such lookup doesn't always produce the needed result, especially when dealing with compound words and proper names. To counteract these deficiencies, authors may use one of the following invisible characters.

In order to manually fine-tune word-boundary detection, the invisible character 200B (ZWSP) can be used to create breaks.u,625

To prevent a break between syllables, 2060 (WJ) can be used.

It is also important to bear in mind that Khmer may be used to write various languages, in particular minority languages for which different dictionaries are needed. Since such dictionaries may not available in a given browser or other application, there is a tendency to use ZWSP in order to compensate.

Large-scale manual entry of ZWSP and WJ has potential downsides because the user cannot see them; this leads to problems with ZWSP being inserted in the wrong position, or multiple times. However, these don't set a state, so it doesn't create major issues. It would be useful, however, if an editor showed the location of these characters.

Care should also be taken when trying to match text, eg. for searching in a page. WJ should be ignored. ZWSP may or may not be ignored, depending on whether word boundaries are significant for the search.

Line-edge rules

As in almost all writing systems, certain punctuation characters should not appear at the end or the start of a line. The Unicode line-break properties help applications decide whether a character should appear at the start or end of a line.

Show (default) line-breaking properties for characters in the modern Khmer orthography.

The following list gives examples of typical behaviours for characters used in modern Cambodian. Context may affect the behaviour of some of these and other characters.

Click on the Khmer characters to show what they are.

“ ‘ ( should not be the last character on a line
” ’ ) ? ! ។ ៕ ៚ % should not begin a new line
៛ should be kept with any number, even if separated by a space or parenthesis.

The following character should not produce a line-break when they appear inside or alongside a word: ៙.

Baselines, line height, etc.

Khmer uses the so-called 'alphabetic' baseline, which is the same as for Latin and many other scripts.

To give an approximate idea, fig_baselines compares Latin and Khmer glyphs from Noto fonts. The basic height of Khmer letters is typically around the Latin ascender height in one, and around the x-height in the other, however extenders and combining marks, extend well beyond the Latin ascenders and descenders, creating a need for larger line spacing.

Xqhxកឺថ្នូឦឳហ្វ៊ីខ្ញុំកឿក្រុង្ខ្យន្ត្រៃភ្លៀ — Font metrics for Latin text compared with Khmer glyphs in the Noto Serif Khmer (top) and Noto Sans Khmer (bottom) fonts.

fig_baselines_other shows similar comparisons for the Khmer MN and Mondulkiri fonts.

Counters, lists, etc.

You can experiment with counter styles using the Counter styles converter. Patterns for using these styles in CSS can be found in Ready-made Counter Styles, and we use the names of those patterns here to refer to the various styles.

The modern Khmer orthography uses numeric and alphabetic styles.

Numeric

The khmer numeric style is decimal-based and uses these digits.rmcs

០␣១␣២␣៣␣៤␣៥␣៦␣៧␣៨␣៩

Examples:

១␣២␣៣␣៤␣១១␣២២␣៣៣␣៤៤␣១១១␣២២២␣៣៣៣␣៤៤៤

Alphabetic

The cambodian-consonant alphabetic style for the Khmer language uses these letters.

ក␣ខ␣គ␣ឃ␣ង␣ច␣ឆ␣ជ␣ឈ␣ញ␣ដ␣ឋ␣ឌ␣ឍ␣ណ␣ត␣ថ␣ទ␣ធ␣ន␣ប␣ផ␣ព␣ភ␣ម␣យ␣រ␣ល␣វ␣ស␣ហ␣ឡ␣អ

Examples:

ក␣ខ␣គ␣ឃ␣ដ␣ផ␣អ␣កដ␣គឋ␣ចភ␣ញគ␣ឌណ

Prefixes and suffixes

List counters typically use a full stop+space as a suffix.

ក. ខ. គ. ឃ. ង.

Separator for Cambodian list counters.