Cambodian (draft)

Khmer

Letters

Combining marks

Numbers

Punctuation

Symbols

Other

Morphological syllables

Many native Cambodian words are monosyllabic. There are also 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 that begin with consonant clusters, and some monosyllabic words that 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 morphological syllable.

    

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

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

1. base consonant or independent vowel
2. rɔɓaːt
3. museʔkətoə̯n or trəisaɓ (register shifters)
4. subscript (consonant or independent vowel)
5. vowel sign
6. zero-width joiner or non-joiner
7. any other mark

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

Glyph order

As mentioned above, 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.

Vowel sounds

Consonant sounds

	labial	dental	alveolar	retroflex	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

Vowel sounds mapped to characters

This section maps Cambodian vowel sounds to common graphemes in the Khmer orthography, grouped by register (class 1 or 2). 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.

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 o-class. The class of a consonant then determines the vowel sound in a syllable. For example, compare the pronunciations in the table:

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.

Inherent vowels

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. ក [U+1780 KHMER LETTER KA] (an ɑː class consonant) is pronounced kɑː whereas គ [U+1782 KHMER LETTER KO] (an ɔː class consonant) is pronounced kɔː, but see also vowel_harmony.

The invisible characters ឴ U+17B4 KHMER VOWEL INHERENT AQ and ឵ 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

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.

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

Vowel-signs

Non-inherent vowel sounds that follow a consonant can be represented using vowel-signs, eg. ki is written កិ [U+1780 KHMER LETTER KA + U+17B7 KHMER VOWEL SIGN I].

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. Where the orthographic syllable begins with a stack of consonants, the vowel-sign, including pre-base vowel-signs and circumgraphs, is rendered relative to the first (full-sized) item in the stack (see stack_vowels for examples). However, they are typed and stored in computer memory in the order of pronunciation.

Khmer vowels are written using dedicated combining characters, the nikahit or reəahmuk diacritics, and some consonants that are pronounced as vowels in certain contexts. These components may be used on their own, or in combination with others (see composite_vowels).

Around half the vowel-signs are spacing marks, meaning that they consume horizontal space when added to a base consonant.

Combining marks used for vowels

Khmer uses the following dedicated combining marks for vowels. As just mentioned, they may be used on their own, or in combination with others (see composite_vowels). Where there are 2 possible pronunciations listed, the left is for a-class consonants, and the right for 0-class.

All these characters are typed and stored after the base consonant they follow during pronunciation, and the glyph rendering system takes care of the positioning at display time. This also applies for stacks, and for the 3 pre-base vowel-signs and the 5 circumgraphs.

ៈ [U+17C8 KHMER SIGN YUUKALEAPINTU​] 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.

៏ [U+17CF KHMER SIGN AHSDA​] is used over just two words: ក៏ ដ៏

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

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.

See also encoding_choices.

Consonants used for vowels

Vowel-signs may sometimes be combined with other characters to represent a particular vowel sound.

Vowel modifier marks

័ [U+17D0 KHMER SIGN SAMYOK SANNYA​] 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 name just above for more details). 

់ [U+17CB KHMER SIGN BANTOC] is always placed above the final consonant, and basically shortens the preceding vowel.

Composite vowels

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

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 regular consonant អ [U+17A2 KHMER LETTER QA] followed by a vowel-sign (and អ៊ [U+17A2 KHMER LETTER QA + U+17CA KHMER SIGN TRIISAP] to change the register), eg. អូ អ៊ូ ចង្អូរ

Silent vowels & consonants

Inherent vowels are not pronounced after syllable final consonants.

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

Vowels are not pronounced between stacked consonants. The first character in the lists above, ្ [U+17D2 KHMER SIGN COENG], is used to create those consonant stacks. It is never visible. See clusters.

Two diacritics, ៌ [U+17CC KHMER SIGN ROBAT​] and ៍ [U+17CD KHMER SIGN TOANDAKHIAT​], are used to silence written characters. The former is not very common and silences final consonants, eg. បរិបូណ៌

(although it also introduces or affects sound in some cases in multisyllabic words). The latter is used over a consonant, particularly in loan words, to silence it and any attached vowels or subscripts, eg. សប្ដាហ៍ រេហ៍ពល កេរ្តិ៍

៑ [U+17D1 KHMER SIGN VIRIAM], the sanskrit virama, is sometimes used in Sanskrit words to indicate that a final consonant has no vowel sound, eg. អាត្មន៑

៝ [U+17DD KHMER SIGN ATTHACAN], on the other hand, is a rarely used sign that indicates that a final consonant retains its inherent vowel sound.

Initial consonant sounds to characters

This section maps Cambodian consonant sounds to common graphemes in the Khmer orthography, grouped by register (class 1 or 2)..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.

Sounds listed as 'infrequent' are allophones, or sounds used for foreign words, Sanskrit, etc.

Changing consonant registers

Khmer is not tonal, but each consonant character belongs to one of two classes. The class of a consonant determines the vowel sound in a syllable. For example, compareក kɑː គ kɔːand កី kəj គី kiː

Two diacritics, ៉ [U+17C9 KHMER SIGN MUUSIKATOAN​] and ៊ [U+17CA KHMER SIGN TRIISAP​], 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.

Each of these diacritics should be typed and stored immediately after the base character (unless there is a ZWNJ, as described in consonant_shift_posn).u,647

Basic consonants

This shows consonants in use in modern Khmer, although some are not widely used.

The 2 registers are shown separately for the plosives, and the remainder are mixed. A superscript ^ɑ or ^ɔ indicates which register the consonant belongs to. 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.

Additional consonants

Special combinations are used to represent non-native sounds in loan words, especially from French and Thai.

Final consonants

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

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, it is difficult to parse Khmer. For example, the sequence កក could equally represent two syllables kɑːkɑː with inherent vowels, or one syllable with a final -k sound kɑːʔ.

Two final consonant sounds m and h can also be produced using combining characters. See anusvara_visarga 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 ្ [U+17D2 KHMER SIGN COENG] between the consonants. This character has no visual representation.

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.

Currency

The symbol ៛ [U+17DB KHMER CURRENCY SYMBOL RIEL] (សញ្ញារៀល sɲ͓ɲāṟiᵊḻ saɲ ɲaː riəl) is placed after the amount, eg. ៣.០០០ ៛ ɓej poan riəl 3,000 riel. Sometimes រ [U+179A KHMER LETTER RO] is used instead.

Other

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

Use of ៓ [U+17D3 KHMER SIGN BATHAMASAT] is discouraged in favor of the complete set of lunar date symbols.

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

Writing styles

There are several distinct styles of font in Modern Khmer.

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.

The slanted style (អក្សរជ្រៀង ʔk͓sṟc̱͓ṟiᵊŋ ʔɑːksɑː criəŋ) is 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) includes more ligated forms, and is 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

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

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.

Register-shifter position

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

When  ៉ [U+17C9 KHMER SIGN MUUSIKATOAN​] museʔkətoə̯n or  ៊ [U+17CA KHMER SIGN TRIISAP​] trəisaɓ appears with a vowel sign above the consonant, the ក្បៀសក្រោម kɓiəhkraom form may be used. This looks exactly like ុ [U+17BB KHMER VOWEL SIGN U​], eg. compare the following uses of MUUSIKATOAN យ៉ាង ម៉ឺន ញ៉ាំ

Here are some examples of TRIISAP អ៊ូ 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.

For more details, see this SIL document.sil

Observation: SIL and Noto fonts, as well as others, stack the diacritics above only certain consonants. The behaviour varies a little by font, but in general the diacritic is lowereed for the following 3 letters for TRIISAP: សហអand these letters for MUUSIKATOAN: បវមនញងរលយ

If needed, this behaviour can be modified using ‌ [U+200C ZERO WIDTH NON-JOINER], 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.

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.

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 ‌ [U+200C ZERO WIDTH NON-JOINER] (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 ‍ [U+200D ZERO WIDTH JOINER] (ZWJ) instead.u,647

Font styles

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Grapheme boundaries

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Word boundaries

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

Sometimes ​ [U+200B ZERO-WIDTH SPACE] 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   [U+2006 SIX-PER-EM SPACE], and separate phrases with a wider space such as   [U+2003 EM SPACE].sil,5

Phrase & section boundaries

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:

1. between clauses within a sentence
2. between sentences in a cohesive group of sentences
3. after preposed adverbial phrases, such as 'usually', 'today', 'in that town', etc.
4. before and after proper names
5. before and after numbers
6. before and after the symbols ។ and ៗ and the terms ។ល។ and ។ប។
7. 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 ។ [U+17D4 KHMER SIGN KHAN] to mark the end of sentences, although a series of sentences on a related topic tend to be separated by space instead.

៖ [U+17D6 KHMER SIGN CAMNUC PII KUUH] 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 ៎ [U+17CE KHMER SIGN KAKABAT​] 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. ៕ [U+17D5 KHMER SIGN BARIYOOSAN] can be used to close a chapter, or an entire text.

Text start and end. Poetic and religious texts typically start with ៙ [U+17D9 KHMER SIGN PHNAEK MUAN] and end with ៚ [U+17DA KHMER SIGN KOOMUUT].

Parentheses & brackets

Quotations

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

៎ [U+17CE KHMER SIGN KAKABAT​] is very rare, but is used over the final consonant of a word like an exclamation mark, to convey excited emphasis, eg. ណែ៎ នុ៎ះន៎

Other inline ranges

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Text spacing

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Abbreviation, ellipsis & repetition

Inline notes & annotations

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Other punctuation

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:

1. Single, indivisible words: eg. ជាតិ c̱āti nationalវិទ្យាល័យ v̱iṯ͓ȳāḻăȳ highschoolកម្ម km̱͓m̱ mission
2. Words with prefixes and suffixes: eg. អន្តរជាតិ ʔṉ͓tṟc̱āti internationalមហវិទ្យាល័យ m̱hv̱iṯ͓ȳāḻăȳ high school កម្មករ km̱͓m̱kṟ workers
3. Compound words (combining 2, 3, or more single words): eg. ជាតិសាសន៍ c̱ātisāsṉ˟ raceកម្មផល km̱͓m̱pʰḻ karmaសកលវិទ្យាល័យ skḻv̱iṯ͓ȳāḻăȳ university

The first two types cannot be broken, but the third type can. For example, |ជាតិ|សាសន៍|, |កម្ម|ផល|, and |សកល|វិទ្យាល័យ|. (Hong)

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.

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

Text alignment & justification

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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.

Styling initials

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