Thai orthography notes

Sample

Select part of this sample text to show a list of characters, with links to more details.
Change size: 32px

ข้อ 1 มนุษย์ทั้งหลายเกิดมามีอิสระและเสมอภาคกันในเกียรติศักด[เกียรติศักดิ์]และสิทธิ ต่างมีเหตุผลและมโนธรรม และควรปฏิบัติต่อกันด้วยเจตนารมณ์แห่งภราดรภาพ

ข้อ 2 ทุกคนย่อมมีสิทธิและอิสรภาพบรรดาที่กำหนดไว้ในปฏิญญานี้ โดยปราศจากความแตกต่างไม่ว่าชนิดใด ๆ ดังเช่น เชื้อชาติ ผิว เพศ ภาษา ศาสนา ความคิดเห็นทางการเมืองหรือทางอื่น เผ่าพันธุ์แห่งชาติ หรือสังคม ทรัพย์สิน กำเนิด หรือสถานะอื่น ๆ อนึ่งจะไม่มีความแตกต่างใด ๆ ตามมูลฐานแห่งสถานะทางการเมือง ทางการศาล หรือทางการระหว่างประเทศของประเทศหรือดินแดนที่บุคคลสังกัด ไม่ว่าดินแดนนี้จะเป็นเอกราช อยู่ในความพิทักษ์มิได้ปกครองตนเอง หรืออยู่ภายใต้การจำกัดอธิปไตยใด ๆ ทั้งสิ้น

Source: UDHR, articles 1 & 2.

Usage & history

1283 – today

The Thai script is used primarily for writing the Thai language, as well as Northern Thai, Northeastern Thai, Southern Thai, and Thai Song, which are separate languages. It is also used to write a number of minority languages in Thailand, Laos and China, as well as Pali, which is widely used in Buddhist temples and monasteries.s

อักษรไทย

The alphabet was derived from the Old Khmer script, which descended from Pallava. Thai tradition attributes the creation of the script to King Ramkhamhaeng the Great (พ่อขุนรามคำแหงมหาราช pʰo kʰun raːm kʰam ŋɛː ma haː raː tɕʰa) in 1283, though this has been challenged.

Both the Thai language and script are closely related to Lao and its script.

More information: Scriptsource • Wikipedia.

Basic features

Thai is an abugida. Consonant letters have an inherent vowel sound. Vowel signs are attached to the consonant to produce a different vowel. See the table to the right for a brief overview of features for the modern Thai orthography.

Thai text runs left to right in horizontal lines.

Spaces separate phrases, rather than words.

❯ consonantSummary

Modern Thai uses 41 basic consonant letters. Each onset consonant is associated with a high, mid, or low class related to tone. Tone is indicated by a combination of the consonant class, the syllable type (live/dead), plus any tone mark.

No conjuncts are used for consonant clusters.

Syllable-initial clusters and syllable-final consonant sounds are all written with ordinary consonant letters. It can therefore be difficult to algorithmically detect syllable boundaries.

❯ basicV

This orthography is an abugida with 3 inherent vowels, pronounced o in a closed syllable and a in an open syllable, and ɔː before a final -r.

Other post-consonant vowel sounds are represented using 8 combining marks, 8 vowel letters, and 4 consonants, very often combined into multipart vowels. There are 5 pre-base vowel glyphs, but no circumgraphs, although the many multipart vowel components often appear on more than one side of the base.

Thai uses visual placement: only the 8 vowel components that appear above or below the consonant are combining marks; the others are ordinary spacing characters that are typed in the order seen.

This page lists 37 multipart vowels (including diphthongs) made from 12 dedicated vowel characters, and 4 consonants. Multipart vowels can involve up to 4 glyphs (plus a tone mark), and glyphs can surround the base consonant(s) on up to 3 sides.

The glyphs used to represent vowels, whether alone or in multipart vowels, are arranged around a syllable onset, which may be 2 consonants, rather than just around the immediately preceding consonant. For an example of the effect this produces, see prebase and compositeV.

There are no independent vowels, and standalone vowel sounds are written using vowel signs applied to อ.

Thai vowels all come in short and long forms, which are phonemically distinctive. A set of diphthongs end in a̯, and most vowels can be followed by either w or j.

Vowel sounds are often written differently when they appear in a closed vs. open syllable. Short vowels in open syllables usually end with a glottal stop.

Thai has vocalics.

Thai has native digits, and they are commonly used.

Character index

Letters

Show

Consonants

ผ␣ถ␣ฐ␣ข␣ป␣บ␣ต␣ด␣ฏ␣ฎ␣ก␣อ␣พ␣ภ␣ท␣ธ␣ฑ␣ฒ␣ค␣ฆ␣ฉ␣จ␣ช␣ฌ␣ฝ␣ส␣ศ␣ษ␣ห␣ฟ␣ซ␣ฮ␣ม␣น␣ณ␣ง␣ว␣ร␣ล␣ฬ␣ย␣ญ

Vowels

เ␣แ␣ใ␣ไ␣โ␣ะ␣า␣ำ

Vocalics

ฤ␣ฦ␣ๅ

Other

ฯ␣ๆ

Not used

ฃ␣ฅ

Combining marks

Show

Vowels

ิ␣ี␣ึ␣ื␣ุ␣ู␣ั␣็

Bindu

ํ

Tones

่␣้␣๊␣๋

Consonant killer

์

Not used for Thai

๎

Numbers

Show

๐␣๑␣๒␣๓␣๔␣๕␣๖␣๗␣๘␣๙

Punctuation

Show

“␣”␣‘␣’␣๚␣๛␣๏␣–␣—␣…

ASCII

,␣:␣.␣?␣!␣(␣)

Symbols

Show

฿

Other

Show

␣⁠

To be investigated

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

Phonology

Click on the sound groups to see where else in the document each of the sounds are referred to.

Source Wikipedia.

Vowel sounds

Plain vowels

	Front	Central	Back
Close	i iː	ɯ ɯː	u uː
Close-mid	e eː	ɤ ɤː	o oː
Open-mid	ɛ ɛː		ɔ ɔː
Open		a aː	ɑ ɑː

Complex vowels

	Front	Central	Back
Close	iə iːə iw iəw	ɯə ɯːə ɯəj	uə uːə uj uːj uəj
Close-mid	ew eːw	ɤːj	oːj
Open-mid	ɛːw		ɔːj
Open		aj aːj aw aːw

The majority of diphthongs and all 3 triphthongs in Thai end in j or w.wl,#Phonology The exceptions are a handful of diphthongs that end in ə.

Consonant sounds

	labial	dental	alveolar	post- alveolar	palatal	velar	glottal
stops	p b	t d				k	ʔ
	pʰ	tʰ				kʰ
affricates				t͡ɕ
				t͡ɕʰ
fricatives	f		s				h
nasals	m		n			ŋ
approximants	w		l		j
trills/flaps			r

Finals

	labial	dental	alveolar	palatal	velar	glottal
stop	p	t			k	ʔ
nasal	m		n		ŋ
approximant	w			j

Tone

Thai is a contour tone language, with 5 tones: high, mid, low, falling, & rising.

Pitch vs time variations — Thai tones. source: Zsiga, The Sounds of Language

The following table provides typical phonological transcriptions and descriptions for the five tones.wl,#Tones

high	á	˦˥	live or dead syllables
			ค้า; มัก
mid	a/ā	˧	live syllables only
			คา
low	à	˨˩	live or dead syllables
			ข่า; หมัก
rising	ǎ	˧˨˧	live syllables only
			ขา
falling	â	˥˩	live or dead syllables
			ค่า; มาก

Structure

Thai syllables allow the following patterns, where V can be a short or a long vowelc,#Thai.

V VC CV CVC CCV CCVC

The long vs. short vowel distinction is phonemically important. Long vowels are approximately twice the length of short ones. All open syllables have long vowels.wl,#Vowel_developments

Consonant clusters only occur in syllable initial position, with the following permissable combinations:c,#Thai

pʰr pʰl
tʰr
kʰr kʰl kʰw

Syllable-final consonants can be one of the following.c,#Thai Stops are unreleased.

-p̚ -t̚ -k̚ -m -n -ŋ -j -w

Vowels

See also vocalics.

Vowel summary table

The following table summarises the main vowel to character assigments.

ⓘ represents the inherent vowel. Not listed here are 18 additional diphthongs (shown in the sections below) that are created by adding a -j or -w glide after vowels shown in this table. ◌ indicates the location of a consonant, but does not necessarily indicate a combining mark.

Simple:	◌ิ␣◌ี␣ ␣◌ึ␣◌ื␣◌ือ␣ ␣◌ุ␣◌ู
	เ◌ะ␣เ◌็␣เ◌␣ ␣เ◌ิ␣เ◌อ␣เ◌อะ␣ ␣ⓘ␣โ◌ะ␣◌็อ␣โ◌
	แ◌ะ␣แ◌็␣แ◌␣ ␣◌็␣อ␣เ◌าะ
	ⓘ␣◌ะ␣◌ั␣◌า
Diphthongs:	เ◌ีย␣เ◌ียะ␣ ␣เ◌ือ␣เ◌ือะ␣ ␣◌ัว␣◌ัวะ
Vocalics:	ฤ␣ฦ␣ฤๅ␣ฦๅ
Standalone:	อ

For additional details see vowel_mappings.

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

ย␣ร␣ว␣อ␣ะ␣เ␣แ␣โ␣ใ␣ไ

ั␣า␣ำ␣ิ␣ี␣ึ␣ื␣ุ␣ู␣็␣ํ

Inherent vowels

ก ko ~ ka ~ kɔː U+0E01 THAI CHARACTER KO KAI

The inherent vowel is pronounced o inside a closed syllable, and a in an open syllable. So ka can be written by simply using the consonant letter ก, and kon by just the 2 consonants, กน. Example of a single word using both inherent vowels:

ถนน

A third inherent vowel, ɔː, occurs before a syllable-final RA (which is pronounced n), eg.

ศร

นคร

Other vowels following consonants

กิ ki U+0E01 THAI CHARACTER KO KAI + U+0E34 THAI CHARACTER SARA I

Post-consonant vowels are written using 8 combining marks, 8 vowel letters, and 4 consonants, very often combined into multipart vowels. There are 5 pre-base vowel glyphs, but no circumgraphs, although the many multipart vowel components often appear on more than one side of the base.

Thai uses visual placement: only the 8 vowel components that appear above or below the consonant are combining marks; the others are ordinary spacing characters that are typed in the order seen.

The glyphs used to represent vowels, whether alone or in multipart vowels, are arranged around a syllable onset, which may be 2 consonants, rather than just around the immediately preceding consonant. For an example of the effect this produces, see prebase and compositeV.

Plain vowels

Some vowels are written differently in open syllables and closed syllables.

The following panel lists monophthongs in open syllables. The dotted circle shows the location of adjacent consonants.

◌ิ␣◌ี␣◌ึ␣◌ือ␣◌ุ␣◌ู␣เ◌ะ␣เ◌␣เ◌อะ␣เ◌อ␣โ◌ะ␣โ◌␣แ◌ะ␣แ◌␣เ◌าะ␣อ␣◌ะ␣◌า

The next panel shows how the same vowels are normally written in closed syllables.

◌ิ◌␣◌ี◌␣◌ึ◌␣◌ื◌␣◌ุ◌␣◌ู◌␣เ◌็◌␣เ◌◌␣เ◌ิ◌␣เ◌ิ◌␣◌␣โ◌◌␣แ◌็◌␣แ◌◌␣◌็อ◌␣◌อ◌␣◌ั◌␣◌รร◌␣◌า◌

The consonant 0E2D can also be pronounced as the vowel ɔː when it appears alone after a base consonant. It is also used as a vowel carrier for standalone vowels (see standalone).

The consonant 0E23 is pronounced as a vowel a when doubled in a closed syllable (see doubleRA).

Diphthongs, triphthongs, & complete rhymes

Thai complex vowels are complicated and numerous. The way they are written also varies according to whether they appear in an open or a closed syllable. The following panel shows open syllable.

Most complex Thai vowels involve adding a final -j or -w glide after a vowel. The following panel shows combinations that don't follow that pattern. Except for uə̯, they are spelled the same whether the syllable is open or closed. However, there are 2 ways of spelling each diphthong in open syllables.

เ◌ีย␣เ◌ียะ␣เ◌ือ␣เ◌ือะ␣◌ัวะ␣◌ัว␣◌ว◌

This next panel shows diphthongs and triphthongs that are produced using a following glide. Nearly all of these simply tack ย or ว onto the end of the vowel. Each of the items shown here constitutes a complete syllabic rhyme.

◌ิว␣เ◌ียว␣◌ึย␣เ◌ือย␣◌ุย␣◌ูย␣◌วย␣◌วาย␣เ◌็ว␣เ◌ว␣เ◌ย␣โ◌ย␣แ◌ว␣◌อย␣◌อย␣ไ◌␣ใ◌␣◌ัย␣ไ◌ย␣ไ◌␣ใ◌␣◌าย␣เ◌า␣◌าว

Note that the above set includes 2 single code points that represent diphthongs: ไ and ใ.

The final panel in this section shows some complete Thai rhymes that have special spellings.

◌ำ␣◌รร

Doubled RA

The consonant 0E23 is pronounced as a vowel a when doubled medially, eg.

ธรรม

When doubled at the end of a syllable it is pronounced an, eg.

กรรไกร

Note, however, that this may also constitute the end and beginning of two syllables, eg.

ภรรยา

Maitaikhu

0E47 appears alone, like a vowel character, over a consonant in one word only, with the pronunciation ɔ̂ː.

ก็

It is more often used to convert the vowels produced by the following three vowel signs to short vowels when they are followed by a final consonant (dotted circles represent consonants here).

เ◌ eː becomes เ◌็◌ e
◌อ◌ ɔː becomes ◌็อ◌ ɔ,
แ◌ ɛː becomes แ◌็◌ ɛ (not very common).

Examples:

เด็ก

ซ็อกเก็ต

น้ำแข็ง

It is also used for the diphthong ew เ◌็ว (eːw > ew).

เร็ว

Sara AM & nikhahit

0E33 is classed as a vowel, but also contains the final consonant m, represented by a built-in nikhahit.

Used in Pali and Sanskrit, 0E4D is not commonly used alone in Thai, except that when letter-spacing Thai text it is necessary to add the space between the circle and the remainder of 0E33. See inter_character_spacing.

The separation is not produced by NFD normalisation (see also encoding_nikahit).

Pre-base vowel glyphs

โก koː U+0E42 THAI CHARACTER SARA O + U+0E01 THAI CHARACTER KO KAI

Five vowel glyphs appear to the left of the onset consonant(s).

เ␣แ␣ใ␣ไ␣โ

Since Thai uses a visual encoding model, these are not combining marks. They are typed and stored before the base. Click on the following word to see the sequence of characters in storage.

ไข่

These vowel characters are actually placed before the start of the syllable. This means that a word with a consonant cluster at the start separates the pre-base vowel from any post-base vowels by more than one consonant character, eg.

เปล่า

fig_prebase graphically illustrates the arrangement of glyphs for the word program.

show composition

โปรแกรม

แ should not be typed as two successive เ characters (see encoding_sarah_ae).

Vowel length

In common with other languages, i, ɯ, u, and a vowels have dedicated characters for long and short sounds. But many multipart vowels use 0E30 or 0E47 as shorteners. The following provides one example of the general pattern.

เ◌␣เ◌ะ␣เ◌็◌

This can be seen clearly by comparing the long and short vowels in vowel_mappings.

Nasalisation

The orthography has no special mechanism to indicate vowel nasalisation.

Multipart vowels

เกียะ kia̯ʔ U+0E40 SARA E + U+0E01 KO KA + U+0E35 SARA II + U+0E22 YO YAK + U+0E30 SARA A

show composition

เกี๊ยะ

Some represent plain vowel sounds:

ือ␣เ◌ะ␣เ◌็␣เ◌ิ␣เ◌อ␣เ◌อะ␣โ◌ะ␣็อ␣แ◌ะ␣แ◌็␣เ◌าะ

The other multipart vowels represent diphthongs, which generally end in one of ə̯, i, or w.

For some, the spelling isn't completely obvious.

เ◌ีย␣เ◌ียะ␣เ◌ือ␣เ◌ือะ␣ัว␣ัวะ

In many other cases, a semivowel is simply added after one of the vowels seen earlier. See diphthongsz for a list.

Finally, the two vocalic letters can be lengthened using an additional, special character (see vocalics).

ฤๅ␣ฦๅ

Characters that don't appear in the combinations:

ร␣ำ␣ึ␣ใ

Show which combinations contain a given character:

ะ	เ-ะ␣โ-ะ␣แ-ะ␣เ-าะ␣เ-อะ␣ ␣เ-ียะ␣เ-ือะ␣-ัวะ
ั	-ัย␣ ␣-ัวะ␣-ัว
า	เ-าะ␣ ␣-าย␣ ␣-าว␣เ-า
ิ	เ-ิ␣ ␣-ิว
ี	เ-ีย␣เ-ียะ␣ ␣เ-ียว
ื	-ือ␣ ␣เ-ือ␣เ-ือะ␣ ␣เ-ือย
ุ	-ุย
ู	-ูย
เ	เ-ะ␣เ-็␣เ-อ␣เ-ิ␣เ-าะ␣เ-อะ␣ ␣เ-ือ␣เ-ีย␣เ-ียะ␣เ-ือะ␣ ␣เ-ย␣เ-ือย␣ ␣เ-ว␣เ-า␣เ-็ว␣เ-ียว
แ	แ-ะ␣แ-็␣ ␣แ-ว
โ	โ-ะ␣ ␣โ-ย
ไ	ไ-ย
็	-็อ␣เ-็␣แ-็␣ ␣-็อย␣ ␣เ-็ว
อ	-ือ␣-็อ␣เ-อ␣เ-อะ␣ ␣เ-ือ␣เ-ือะ␣ ␣-อย␣-็อย␣เ-ือย
ย	เ-ีย␣เ-ียะ␣ ␣-ัย␣-าย␣-อย␣-ุย␣-ูย␣-วย␣เ-ย␣โ-ย␣ไ-ย␣-็อย␣เ-ือย␣ ␣เ-ียว
ว	-ัว␣-ัวะ␣ ␣-วย␣ ␣-ิว␣-าว␣เ-ว␣แ-ว␣เ-็ว␣เ-ียว
ร	-รร-␣-รร

Show details about glyph positioning

The following list shows where vowel sign glyphs 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 Unicode characters,

5 pre-base, eg. โก ok̯ (ko)
2 post-base, eg. กา k̯ā
5 superscript, eg. กิ k̯i
2 subscript, eg. กุ k̯u
1+5 sup+post-base, eg. กือ k̯ɯ̄ʔ̯ kɯːo
+4 post+post-base, eg. กาว k̯āw̱ kaːw
+2 sub+post-base, eg. กุย k̯uy̱ kuj
+10 pre+post-base, eg. เกะ ek̯a kè
+3 pre+superscript, eg. เกิ ek̯i kɤː
+2 super+post+post, eg. กัวะ k̯äw̱a kua
+2 pre+post+post, eg. เกาะ ek̯āa kɔ̀
+3 pre+sup+post-base, eg. เกือ ek̯ɯ̄ʔ̯ kɯːa
+4 pre+sup+post+post-base, eg. เกียะ ek̯īy̱a kiːa

At maximum, vowel components can occur concurrently on 3 sides of the base.

Distribution of vowel elements is as follows:

	ั ิ ี ึ ื ็	ำ
เ แ ใ ไ โ		อ ะ า ย ว ๅ	ะ ย
	ุ ู

Standalone vowels

อ

Thai uses 0E2D as a base for vowel signs, eg.

อิ่ม

เออออ

สะอาด

อ on its own represents the same sound as the inherent vowel, eg. อเมริกา

There are no independent vowel letters in Thai,

Tones

Each onset consonant is associated with a 'high', 'mid', or 'low' class, which is related to, but not indicative of, tone. (For example, when they appear without tone marks the 'high' class consonants produce a rising tone, and 'mid' or 'low' class consonants both produce a mid tone.)

Tone is also affected by the use of the following combining marks on live syllables, however in 2 cases the result of their use is also context-dependent, due to historical linguistic changes. (For example, 0E48 can produce either a low tone or a falling tone, depending on the class of the onset.)

่␣้␣๊␣๋

In the end, tone is indicated by a combination of the consonant class, the syllable type (live/dead), vowel length (for dead syllables), plus any tone mark.

Figure out the tone, depending on the sequence of characters used.

Consonant	Dead?	Tone mark	Tone
high	dead	short	˩˩ low
	dead	long	˩˩ low
	live	-	˩˥ rising
		่	˩˩ low
		้	˥˩ falling
mid	dead	short	˩˩ low
	dead	long	˩˩ low
	live	-	˧˧ mid
		่	˩˩ low
		้	˥˩ falling
		๊	˦˥ high
		๋	˩˥ rising
low	dead	short	˦˥ high
	dead	long	˥˩ falling
	live	-	˧˧ mid
		่	˥˩ falling
		้	˦˥ high

Dead syllables

The following table shows the various ways of writing tones in dead syllables. Only 3 tones are available, and no diacritics are used. Vowel length changes the tone after a low register consonant.

	consonant	vowel length
high tone	LOW	short
low tone	HIGH	–
	MID	–
falling tone	LOW	long

Live syllables

The next table shows the various ways of writing tones in live syllables. All 5 tones are possible.

	consonant	diacritic
high tone	MID	0E4A
	LOW	0E49
mid tone	MID	–
	LOW	–
low tone	HIGH	0E48
	MID	0E48
rising tone	HIGH	–
	MID	0E4B
falling tone	HIGH	0E49
	MID	0E49
	LOW	0E48

Tone mark position

The expected typing and storage position for tone marks is immediately after the base consonant of the syllable, or after a superscript or subscript vowel mark if there is one.

The tone mark should be typed before ำ, but should be displayed above the nikhahit by the application, eg. ก่ำ

Vowel absence

์

Vowel absence after syllable-final consonants is not normally marked in any way. Nor is it marked in syllable-initial clusters.

0E4C can be used above a consonant or syllable when it is not pronounced (usually at the end of a syllable).

Click on the words to see the pronunciation more clearly.

รถเมล์ศักดิ์สิทธิ์ It is often used for foreign loan words, eg. คอมพิวเตอร์ โปสการ์ด สแตมป์

Vowel sounds mapped to characters

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

The left column shows vowels in open syllables. The right column shows vowels 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

0E34

กสิ

See also vocalics.

0E34

ลิง

iː

0E35

คิรี

0E35

หีบ

0E36 (rare in open syllables)

คร่ำครึ

See also vocalics.

0E36

ผึ้ง

ɯː

0E37 0E2D

คือ

See also vocalics.

0E37

คืน

0E38

คุรุ

0E38

ถุง

uː

0E39

งู

0E39

คูณ

0E40 25CC 0E30

งู

0E40 25CC 0E47

คูณ

0E40 25CC in some cases, although the form with maitaikhu is more common.

เข่ง

eː

0E40 25CC

เก

0E40 25CC

เมฆ

0E40 25CC 0E2D 0E30

เกอะ

0E40 25CC 0E34 (rare)

เงิน

ɤː

0E40 25CC 0E2D

เฌอ

0E40 25CC 0E34 (rare)

เหิน

0E42 25CC 0E30

โละ

Inherent vowel

ถนน

oː

0E42 25CC

โต

0E42 25CC

จั่วโมง

0E41 25CC 0E30

แพะ

0E41 25CC 0E47

แล็บ

0E41 25CC sometimes.

แก่น

ɛː

0E41 25CC

แร

0E41 25CC sometimes.

แพง

0E40 25CC 0E32 0E30 (rare)

เกาะ

0E47 0E2D

ซ็อกเก็ต

0E2D sometimes.

คลอง

ɔː

0E2D

พ่อ

0E47 (only in the word ก็).

0E2D

พอง

Inherent vowel before a final 0E23.

นคร

0E30

จะ

Inherent vowel (usually mid-word).

ถนน

0E31

ฟัน

0E23 0E23

ธรรม

aː

0E32

ขา

0E32

บาท

0E33

ตำบล

0E23 0E23

กรรไกร

Diphthongs and triphthongs

ia̯

0E40 25CC 0E35 0E22

เมีย

0E40 25CC 0E35 0E22 0E30 (rare)

เจี๊ยะ

0E40 25CC 0E35 0E22

เขียน

ɯa̯

0E40 25CC 0E37 0E2D

เรือ

0E40 25CC 0E37 0E2D 0E30 (very rare)

เลอเวือะ

0E40 25CC 0E37 0E2D

เชือก

ua̯

0E31 0E27 0E30

โอยัวะ

0E31 0E27

จั่วโมง

0E27

สวน

Rhymes ending in semivowels

0E34 0E27

คอมพิวเตอร์

ia̯w

0E40 25CC 0E35 0E22 0E27

เขียว

ɯj

0E36 0E22 (very rare)

สยึ๋มกึ๋ย

ɯa̯j

0E40 25CC 0E37 0E2D 0E22 (only found in about 20 common words in Thai)

เรื่อย

0E38 0E22

คุย

uːj

0E39 0E22

อูย

ua̯j

0E27 0E22

สวย

uaːj

0E27 0E32 0E22 (this is actually Cw+aːj)

ควาย

0E40 25CC 0E47 0E27

เร็ว

eːw

0E40 25CC 0E27

เหว

ɤːj

0E40 25CC 0E22

เลย

oːj

0E42 25CC 0E22 (rare)

โบย

ɛːw

0E41 25CC 0E27

แมว

ɔj

0E2D 0E22

ค่อย

ɔːj

0E2D 0E22

ลอย

0E44 25CC

ไก่

0E43 25CC

ใบ

0E31 0E22

ภัย

0E44 25CC 0E22 variant spelling.

ไก่ย

aːj

0E44 25CC

ไฟล์

0E43 25CC

ใต้

0E32 0E22

ขาย

0E40 25CC 0E32

เต่า

aːw

0E32 0E27

ยาว

Wiktionary provides a very useful table of Thai rhymes.

Vocalics

ฤ␣ฦ␣ๅ

In Wiktionary all the words that are written with ฦ are described as obsolete spellings.

The long forms of both are created using ๅ. That character is only used in this context.

ฤตู

อังกฤษ

ฤๅษี

ระฦก

ฦๅชา

Consonants

Consonant summary table

The following table summarises the main consonant to character assigments.

The first few rows are for initial consonants. They are split across high, mid, and low columns. The later rows are for syllable-final consonants.

Stops	ผ␣ถ␣ฐ␣ข	ป␣บ␣ต␣ฏ␣ด␣ฎ␣ก	พ␣ภ␣ท␣ฑ␣ฒ␣ค␣ฆ
Affricates	ฉ	จ	ช␣ฌ
Fricatives	ฝ␣ส␣ศ␣ษ␣ห		ฟ␣ซ␣ฮ
Nasals	หม␣หน␣หง		ม␣น␣ณ␣ง
Other	หว␣หร␣หล␣หย␣หญ		ว␣ร␣ล␣ฬ␣ย␣ญ
Finals	ป␣พ␣ภ␣บ␣ถ␣ฐ␣ต␣ฏ␣ท␣ธ␣ฑ␣ฒ␣ด␣ฎ␣ถ␣ฐ␣ต␣ฏ␣ท␣ธ␣ฑ␣ฒ␣ด␣ฎ␣จ␣ช␣ส␣ศ␣ษ␣ซ␣ข␣ก␣ค␣ฆ
	ม␣น␣ณ␣ร␣ล␣ฬ␣ญ␣ง
	ว␣ย

For additional details see vowel_mappings.

Basic consonants

Whereas the table just above takes you from sounds to letters, the following simply lists the basic consonant letters.

Each of the basic consonants is associated with one of 3 classes (high, mid, and low), that play a part in indicating the tone of the syllable (see tones). In not all cases does this lead to more than one letter for a given consonant.

The pronunciation of a letter often differs when the consonant is the onset or coda of a syllable.

In the following lists, the class of each consonant is shown just below the IPA data. If a dash appears after the IPA transcription, it indicates the pronunciation in syllable-initial position; before indicates the pronunciation for syllable codas.

ผ␣ป␣พ␣ภ␣บ␣ ␣ถ␣ฐ␣ต␣ฏ␣ท␣ธ␣ฑ␣ฒ␣ด␣ฎ␣ ␣ข␣ก␣ค␣ฆ␣ ␣ฉ␣จ␣ช␣ฌ␣ ␣ฝ␣ฟ␣ส␣ศ␣ษ␣ซ␣ห␣ฮ␣ ␣ม␣น␣ณ␣ง␣ ␣ว␣ร␣ล␣ฬ␣ย␣ญ

High class nasals & liquids with HO

A silent ห is added before the characters in the list below to make their default tonal class high.

หม␣หน␣หง␣หว␣หร␣หล␣หย␣หญ

Examples: หมาหยุด

See onsets for further details about how these are presented.

The letter O ANG

อ

อ represents a glottal stop or is silent when used as a base for vowels at the beginning of a syllable (see standalone).

อ่าง

When it appears alone after a base consonant it becomes the vowel ɔː (see otherV).

พอง

It is also used in combination with other characters to produce additional vowel sounds (see compositeV).

Obsolete characters

These consonants are now regarded as obsolete.

ฃ␣ฅ

0E03 is replaced by 0E02.

ฃวา

0E05 is replaced by 0E04.

ฅน

Onsets

Consonant clusters at the start of a syllable are usually one of the following:

Glides

An initial stop may be followed by one of -r, -l, or -w. These sounds can be represented using the normal letters, 0E23, 0E25, and 0E27.

ประฏัก

ปลา

ควาย

There are no dedicated code points for glides when they are used after an initial consonant, so it is feasible that ปลา could be pronounced pà laː in a different context.

The vocalics can also be used after an initial consonant, and again can create ambiguity for pronunciation, eg. compare พฤหัสพฤษภา

Tone markers

The silent 0E2Bis used to affect tonal values (see highclass).

หมา

Similarly, a silent 0E2D is used before an initial 0E22 in 4 words to change the tone of the syllable to low.

อย่าง

Initial s

The word-initial combination 0E17 0E23 is pronounced s.

ทราย

Tone & vowel positioning

Tone marks and/or super-/subscript vowel marks are attached to the second consonant.

เปลี่ยน

กรุงเทพฯ

Pre-base vowel glyphs are placed before the first consonant in the cluster, ie. at the start of the syllable, eg. (where this occurs twice):

โปรแกรม

Finals

Only the phonemes p, t, k, m, n, ŋ occur at the end of a syllable, however many more consonant letters can appear in final position.

The following consonant letters are pronounced differently in syllable-initial and syllable-final positions.

จ␣ช␣ศ␣ษ␣ส␣ร␣ล␣ญ

For example,0E25 in:

ลิง

ตำบล

Consonants at the end of a syllable use ordinary code points, eg.

ตื่น

This can create some ambiguity, since there is no distinction between the sequence in the previous example and one where น is a new syllable with an inherent vowel.

The one exception is the character that is normally regarded as a vowel, 0E33, which includes the final m sound, eg. ห้องน้ำ (A final m is not always represented using sara am) eg. ห้าม

Consonant clusters

Consonant clusters occur syllable-initially, or where one syllable ends with a consonant and the next begins with one.

Thai doesn't have conjuncts, stacking, or special code points for final consonants, etc.

0E3A is used as a virama when writing Pali. It is not used in modern Thai.

Final+initial consonant folding

A consonant that appears at both the end of one syllable and the beginning of the next may be expressed with a single character, even if the sounds in each phonetic location differ, eg. สinพิสดาร or ล in จุลทัศน์

Only the following set of consonants behave in this way.

จ␣ช␣ศ␣ษ␣ส␣ล

Consonant length

The Thai orthography has no special features for dealing with geminated or long consonant sounds, however see also folding.

Consonant sounds mapped to characters

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

Rows with 2 columns are high class and low class, respectively. For stop and affricate onsets, rows with a single, centred column are mid class.

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.

Stops

0E1B

ปลา

0E1A

ไบใม้

0E15

เต่า

0E0F (rare as onset)

ปะฏัก

0E14

เด็ก

0E0E

ชะฎา

0E01

ไก่

Aspirated stops

pʰ

0E1A

ผึ้ง

0E1E

พาน

0E20

สำเภา

tʰ

0E16

ถุง

0E10 (rare as onset)

ฐาน

0E17

ทหาร

0E18

ธง

0E12

ผู้เฒ่า

0E11 (rare as onset)

มณโฑ

kʰ

0E02

ไข่

0E04

ควาย

0E06 Used mainly in old words.

ระฆัง

Affricates

t͡ɕ

0E08

จาน

t͡ɕʰ

0E09

ฉิ่ง

0E0A

ช้าง

0E0C Only used in a few words.

เฌอ

Fricatives

0E1D

ฝา

0E1F

ฟัน

0E28

ศาลา

0E29 Less common. Mostly in foriegn words.

ฤๅษี

0E2A Less common. Mostly in foriegn words.

เสือ

0E17 0E23

ทราย

0E0B

โซ่

0E2B

หีบ

0E2E Only used in a few words.

นกฮูก

Nasals

0E2B 0E21

ไหม

0E21

ม้า

0E2B 0E19

หนู

0E13 Mostly used in coda.

เณร

0E19 Rare as onset.

0E2B 0E07

เหงา

0E07

งู

Other

0E2B 0E27

แหวน

0E27

ว่าง

0E2B 0E23

0E23

เรือ

0E2B 0E25

0E25

ลิง

0E2C Now almost obsolete.

จุฬา

0E2B 0E22

หยุด

0E2B 0E0D

หญิง

0E22

ยักษ์

0E0D

ประเทศญี่ปุ่น

Vocalics

0E24

อังกฤษ

rɯ

0E24

ฤดู

rɯː

0E24 0E32

ฤๅษี

Final stops

-p

0E1B

ทวีป

0E1A

ดิบ

0E1E

กรุงเทพฯ

0E20

ลาภ

-t

0E16

รถ

0E10

ประเสริฐ

0E2A

โอกาส

0E28

อากาศ

0E29

พิษ

0E15

ชีวิต

0E14

ตลาด

0E0F

ปรากฏ

0E08

ดุจ

0E17

บาท

0E18

โกรธ

0E11

ครุฑ

0E0A

ประโยชน์

0E0E Almost obsolete as a coda.

กฎ

0E12 Almost obsolete as a coda.

-k

0E02

บรมสุข

0E01

หก

0E04

พรรค

0E06

เมฆ

Final nasals

-m

0E21

ยิ้ม

-n

0E23

นคร

0E25

ตำบล

0E2C

ลคุฬ

0E0D Rare as a coda.

บังเอิญ

0E13

คุณ

0E19

อ้วน

-ŋ

0E07

ลิง

Encoding choices

This section offers advice about characters or character sequences to avoid, and what to use instead. It takes into account the relevance of Unicode Normalisation Form D (NFD) and Unicode Normalisation Form C (NFC)..

Although usage is recommended here, content authors may well be unaware of such recommendations. Therefore, applications should look out for the non-recommended approach and treat it the same as the recommended approach wherever possible.

SARA AE

In complex scripts, visually similar or identical glyph patterns can often be made from a sequence of code points rather than the single code point that Unicode provides. These are not made the same by normalisation, and they are not semantically equivalent. These inappropriate sequences should be avoided because they will cause the meaning of the text to change; searches, matching and other aspects of the text will fail to be understood by the application or the font.

Only one such is listed in the table below, The single code point on the left should be used, and not the sequence on the right. In some cases, fonts will indicate that there is a problem by forcing the appearance of a dotted circle or otherwise failing to render the text correctly, but this may not always be the case.

Use	Do not use
แ	เเ

Nikahit

The combination of nikahit and sara aa is normally written with the precomposed character in the Thai block. It is possible to use 2 code points to create something that may visually look identical (and is in fact used during justification), but the single character and the sequence are not converted to each other during normalisation; therefore, the text will be read as different by normalisation-based matching algorithms.

Recommended	Not recommended
ำ	ํา

Code point sequences

As already mentioned, Thai is visually encoded so pre-base glyphs are associated with ordinary spacing characters, and these need to be typed and stored in visual order relative to the base consonant(s) in a syllable. If the syllable begins with a consonant cluster such as pr, the pre-base code points must be typed before the p, even though they are pronounced after the r.

Tone marks should be typed and stored after any combining vowel mark. Fonts will typically indicate visually that the order is incorrect because the tone mark will appear below the vowel mark if they are the wrong way around.

Numbers, dates, currency, etc.

Thai has a set of decimal digits, that are used regularly.

๐␣๑␣๒␣๓␣๔␣๕␣๖␣๗␣๘␣๙

The CLDR standard-decimal pattern is #,##,##0.###. The standard-percent pattern is #,##,##0%.cldr

Currency

The currency symbol for baht is encoded in the Unicode Thai block.

฿

The CLDR standard format for currency is ¤#,##0.00.cldr

Dates

Thailand commonly uses the Buddhist Era calendar. The Gregorian year 2000 was 2543 in the Buddhist calendar.

วันพุธที่ 15 มีนาคม พ.ศ. 2538 ขึ้น 15 ค่ำ เดือน 4 ปีจอ — Buddhist era date at the top of a Thai newspaper: 15 March 1995.

In fig_thai_date the abbreviation พ.ศ. p̱ʰ.ś. stands for Buddhist era.

Text direction

Thai text runs left to right in horizontal lines.

Show default bidi_class properties for characters used by the modern Thai language.

Glyph shaping & positioning

This section brings together information about the following topics: font/writing styles; cursive text; context-based shaping; context-based positioning; letterform slopes, weights, & italics; case & other character transforms.

You can experiment with examples using the Thai character app.

Font styles

Modern type styles often omit the loops found in more traditional typefaces. See an article that explores this in depth.

Loopless is considered to be more contemporary and modern, and is mainly used for advertising and titling. The distinction doesn’t necessarily map to that of serif vs sans – Noto, for example, provides both serif and sans Thai font faces, but they both have loops. On the other hand, Neue Frutiger Thai offers traditional (looped) and modern (loopless) alternatives as part of the same font family (each with both regular, italic and bold substyles).

ทุกคนมีสิทธิที่จะออกจากประเทศใด ๆ ไป รวมทั้งประเทศของตนเองด้วย และที่จะกลับยังประเทศตน — The Silom font uses the traditional looped glyphs.

Context-based shaping & positioning

Thai has no stacking or conjunct behaviour, but the following are a few selected examples of contextual shaping and positioning.

Most of the combining characters in Thai are used for vowel signs and tone marks. Combining characters need to be placed in different positions, according to the visual context. The example below shows the same tone character displayed at different heights, according to what falls beneath it.

ให้มีขึ้น — The same tone mark displayed at different heights.

Thai regularly combines multiple combining characters above a base consonant. There are two examples in the text below, both of which show a base character with a vowel sign and then a tone mark on top.

ครั้งที่ — Multiple diacritics (vowel sign + tone mark) attached to the same base character.

Although Thai has very little in the way of shaping, fig_shaping shows a number of small glyph adaptations that occur in some fonts (here, Noto Serif Thai) when certain tall or deep consonant letters have vowel marks attached. The 2 examples on the left show a slight reduction in the downward extent of the consonant glyph; in the middle 2 examples the part of the consonant glyph that lies below the baseline is removed altogether and replaced by the vowel sign; and in the right-most example, the height of the consonant glyph is reduced when a vowel sign appears above it.

ฎฎุ ฏฏุ ญญุ ฐฐุ ฬฬึ — Shaping changes in the Noto Serif Thai font. Each example shows an unadorned consonant glyph on the left, and on the right a shaped version when a vowel sign is attached.

Letterform slopes, weights, & italics

Ben Mitchell describes how italicisation is used for meta text and to convey the ‘about’ voice, rather than for emphasis or names of things (for which bold is used).

Italicisation tends to be applied to whole paragraphs or groups of paragraphs, for such things as picture captions, bylines, and other labels, commentaries, summaries such as standfirsts in magazines or news stories, and signposting. It is also regularly used for direct speech between quote marks.

Observation: Thai newspapers appear to use italic text for captions and by-lines. There is no evidence of the use of inline italicisation, but there is inline bolding.

Typographic units

Word boundaries

Thai doesn't separate words in a phrase.

Spaces are used in Thai as phrase separators, but Thai doesn't separate words in a phrase using visible spaces.

There is, however, a concept of words in the text. For example, lines are supposed to be broken at word boundaries.

รวมทั้งวิทยาการด้านคอมพิว — Word boundaries occur where the vertical lines appear, though they are not marked by the script.

Word boundary detection

The main difficulty arises when dealing with compound words. It can often be difficult to decide whether a given string of syllables represents multiple words or a single compound word.

ตัวอย่างการเขียนกาษาไทย — Alternative line break opportunities for Thai text using compound nouns.

The variation may be related to the operation being performed on the text (eg. line breaking in narrow newsprint columns, vs. double-click selection, vs. cursor movement, etc.), or it may just be down to personal preference,

The difference may also be contextually dependent. Wirote Aroonmanakun describes how คนขับรถ should be viewed as a single word in the context คนขับรถนั่งคอยอยู่ในรถ, whereas in the phrase คนขับรถผ่านแยกนี้ไม่มากนัก it would be viewed as 3 words, referring to anyone who is driving.at

Proper names, which are composed from multiple words, are also problematic, especially because there are no capital letters to distinguish them from other pieces of text.g2455,#issuecomment-375162188

ZWSP & WJ

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 Thai 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.

Parsing syllables

Automatically adding spaces (zero-width or other) around Thai syllables is problematic because syllable-final consonants are not easy to identify. Thai segmentation may have to deal with ambiguous situations. Take for example the word ถนน

Because syllable-final sounds are ordinary letters, with no special indication, this could be parsed as ta.non, ton.na, or even ta.na.na, and indeed some words are written the same but pronounced differently, eg. นม

Similarly, because medial consonants are written with normal characters, there is a possibile ambiguity about whether a sequence contains an inherent vowel, eg. กรี

Graphemes

Non-combining Thai vowel characters are treated as independent grapheme clusters. Only combining characters are grouped together with their base into a cluster.

Grapheme clusters

Base SARA_AM? Combining_mark*

Combining_mark may include zero or more of the following types of character, grouped by labels that correspond to Unicode Indic syllabic category values.

Dependent vowels [9] (see combiningV) Thai has many multipart vowels that are made of combinations of ordinary letter characters and combining marks clustered around a base, but in the modern Thai language only one of these dependent vowels is used per base. (Other languages may use more than one. The letter characters are ordinary spacing characters, that are manually positioned in the text stream.)
Tone marks [4] (see tones) Tone marks should be typed and stored immediately after a dependent vowel, if there is one, and immediately after the base otherwise.
Consonant killer (májtʰantʰákʰâːt) [1] (see novowel) Used after other elements in the grapheme cluster to indicate cancelling of a consonant or syllable.

The spacing letters used for vowel signs are all individual grapheme clusters, with the exception of ำ (see nikhahit), which has the general category of Letter, but it is treated like a combining mark during segmentation.

The following examples show a variety of grapheme clusters:

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

	ได้กลิ่น
	ห้องน้ำ
	โปรแกรม
	ศักดิ์สิทธิ์

The grapheme cluster boundaries are convenient for justification algorithms, which insert equal amounts of space between non-combining letters, including between non-combining vowel sign components and their consonants (see justification).

One exception is the aforementioned ำ, which is split across 2 typographic units for the purpose of justification (see inter_character_spacing).

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.

ได้⁠กลิ่นห้องน้ำโปรแกรมศักดิ์สิทธิ์

The first word in the sample text contains 2060 and the first and third words are followed by 200B.

Cursor movement. Move the cursor through the text.
Gecko and WebKit browsers step through the text using grapheme clusters with one exception: they take 2 steps to get through ำ. Blink steps through all words using standard grapheme clusters. In all cases, the WJ and ZWSP are skipped separately; the cursor doesn't appear to move as the arrow key is pressed for Gecko and Blink browsers, but WebKit pauses halfway through the preceding character when it encounters ZWSP.

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, WebKit and Blink browsers all wrap on grapheme cluster boundaries.

Punctuation & inline features

Phrase & section boundaries

,␣:␣.␣?␣!␣๚␣๛

Thai uses space as a phrase marker, rather than to delimit words, often in places where English text would use commas or periods. Latin-based punctuation such as comma, period, and colon are also used in text, particularly in conjunction with Latin letters or in formatting numbers, addresses, and so forth.

phrase	0020 , :
sentence	0020 . ? !
section	๚
chapter/document	๛

๚ is used to mark the end of a long segment of text. It can be combined as follows to mark a larger segment of text; typically this usage can be seen at the end of a verse in poetry.u,625

๚ะ

๛ marks the end of a chapter or document, where it always follows the ๚ะ combination.u,625

Dashes include

‐␣–␣—

Space widths

It is possible to find two different sizes of space in Thai: large spaces between sentences, and small spaces in other places (eg. for separating sub clauses). The width of the small space is the same as ก, and the larger space is double that size.@GitHub,https://github.com/w3c/sealreq/issues/46

Most people no longer make this distinction, but some may want to. It also occurs in other Southeast Asian scripts.

An example of how multiple width spacing may look.

Observation: It is currently not clear how to achieve this on the Web, where multiple space characters are collapsed to a single space by default. One suggestion is to use [U+2003 EM SPACE], but that is not well supported by Thai fonts, and doesn't expand during justification. See @GitHub,https://github.com/w3c/sealreq/issues/46 for a discussion.

Bracketed text

(␣)

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

	start	end
standard	(	)

Quotations & citations

“␣”␣‘␣’

Thai texts 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	‘	’

Abbreviation, ellipsis & repetition

Repetition

ๆ

ๆ is used to mark repetition of preceding letters.u,625 It is typically preceded and followed by a space, eg. ทุกวัน ๆ However, some publishers prefer to publish without a leading space,g19,#issuecomment-579378205 ie. ทุกวันๆ

This character shouldn't be wrapped to the beginning of a new line on its own, and should be kept not far from the preceding text that it duplicates during justification.g19,#issuecomment-579378205

Abbreviation

ฯ

ฯ is used to indicate elision or abbreviation of letters; it is viewed as a kind of letter, however, and is used with considerable frequency because of its appearance in such words as the Thai name for Bangkok, กรุงเทพฯ k̯ṟuŋ̱eṯʰp̱ʰ⋯ krūŋ tʰêːp which is short for กรุงเทพมหานคร k̯ṟuŋ̱eṯʰp̱ʰm̱hāṉḵʰṟ krūŋ tʰêːp mahǎː nákʰɔ̄ːnIt is followed by a space.

Ellipsis

ฯ␣…

Paiyannoi is also used in the combination ฯลฯ to create a construct called paiyanyai , which means “et cetera, and so forth.”u,625

Some abbreviations are written using a full stop, eg. สนง.ตปท. sṉŋ̱.t̯p̯ṯʰ. Office of the Royal Thai Police which is short for สำนักงานตำรวจแห่งชาติ saᵐṉäk̯ŋ̱āṉt̯aᵐṟw̱c̯ɛh¹ŋ̱c̱ʰāt̯i

CLDR indicates that … is also used for ellipsis.

Other inline features

Other punctuation

CLDR indicates that the following are also used:

′␣″␣๎

0E4E is an ancient punctuation mark used to mark clusters, such as in พ๎ราห๎มณ p̱ʰ๎ṟāh๎m̱ṇ̱ pʰraːmǒn

Line & paragraph layout

Line breaking & hyphenation

Even where Thai doesn't indicate word boundaries, when Thai text is wrapped at the end of a line it should break at word boundaries.

As the width of a browser window changes, the text in fig_thai_wrap should break at the points shown if the browser supports Thai wrapping:

โลกจะใช้เพียง — Break points detected in a sequence of Thai characters by an automatic word segmenter.

Because Thai 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 (see #word). For more details, see wordBoundary.

To counteract these deficiencies, authors may use 200B and 2060 (see zwsp).

Note that most browsers have heuristics for segmenting Thai text, but there is no guarantee that these rules will work equally well for other languages that are written in the Thai script.

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 line-breaking properties for characters in the Thai language.

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

Click on the Thai 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 repetition character, ๆ is always preceded by space, however it should not wrap to the next line on its own.@Github,https://github.com/w3c/sealreq/issues/45

Text alignment & justification

Justification in Thai primarily adjusts the blank spaces between phrases, rather than expanding the text between words or syllables. The fact that lines break at word boundaries helps reduce the size of the gaps produced.

Thai may also make certain adjustments to inter-character spacing. The character-based spacing is most common in narrow columns, such as newsprint, where there is no space except at the end of a line.

Any 200B (ZWSP) is used to separate words is ignored during justification. Justification proceeds as if it wasn't there.u,625

Inter-character spacing

The justification in fig_justification_intercharacter_spacing shows equal spacing across a phrase where there are no space characters to stretch. Note how the equal spacing separates pre-base and post-base vowel sign components from their consonants by the same amount as consonants are separated from each other; they are not kept together with the base consonant they modify.

แนะโบรกฯรวมตัวตั้งสนง.ตปท. — A line with no spaces applies inter-character spacing to justify the text.

This kind of spacing requires a special behaviour for ำ. The small circle is kept with the preceding consonant, and space is added before the spacing part of the vowel, as shown in fig_am_spacing.

น้ำ นํ้า — Sara AM before (left) and after (right) inter-character spacing has been applied.

(To facilitate this, applications tend to convert ำ to the sequence ํา before stretching. Some care has to also be taken to correctly order the superscript glyphs, since in memory the tone mark precedes the nikhahit. The nikhahit character is not otherwise used for modern Thai.)

Paragraph indentation

Thai does indent the initial line of a paragraph.

Examples of indented paragraph start. — Indentations at paragraph start in a Thai newspaper.

Baselines, line height, etc.

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

Thai places vowel and tone marks above base characters, one above the other, and can also add combining characters below the line. The complexity of these marks means that the vertical resolution needed for clearly readable Thai text is higher than for English, or most Latin text. In addition, Thai tends to adds more interline spacing than Latin text does.

To give an approximate idea, fig_baselines compares Latin and Thai glyphs from Noto fonts. The basic height of Thai letters is typically around the Latin x-height, however extenders and combining marks reach well beyond the Latin ascenders and descenders, creating a need for larger line spacing. In other fonts, the basic height of the Thai letters tends to be between the Latin x-height and cap-height, and the overall height of the Thai line is therefore greater.@GitHub,https://github.com/w3c/sealreq/issues/55#issuecomment-1356183447 See for example the Angsana New and FreesiaUPC font samples below.

Hhqxใฏูกิ้ปีฬุฬึ์๕๙ — Font metrics for Latin text compared with Thai glyphs in the Noto Serif Thai (top) and Noto Sans Thai (bottom) fonts.

fig_baselines_other shows similar comparisons for the Thonburi and Angsana New 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 Thai orthography uses numeric and alphabetic styles.

Bullets

๏ is the Thai bullet, which is used to mark items in lists or appears at the beginning of a verse, sentence, paragraph, or other textual segment.u,625

Numeric

The thai numeric style is decimal-based and uses the digits shown below.

๐␣๑␣๒␣๓␣๔␣๕␣๖␣๗␣๘␣๙

Examples:

๑␣๒␣๓␣๔␣๑๑␣๒๒␣๓๓␣๔๔␣๑๑๑␣๒๒๒␣๓๓๓␣๔๔๔

Alphabetic

The thai-alphabetic style uses the letters shown below.

ก␣ข␣ค␣ง␣จ␣ฉ␣ช␣ซ␣ฌ␣ญ␣ฎ␣ฏ␣ฐ␣ฑ␣ฒ␣ณ␣ด␣ต␣ถ␣ท␣ธ␣น␣บ␣ป␣ผ␣ฝ␣พ␣ฟ␣ภ␣ม␣ย␣ร␣ล␣ว␣ศ␣ษ␣ส␣ห␣ฬ␣อ␣ฮ

Examples:

ก␣ข␣ค␣ง␣ฎ␣น␣ล␣กค␣ขภ␣จด␣ซจ␣ญว

Styling initials

It is possible to find the first letter in a paragraph styled so that it is larger and sits alongside several lines of the continuing paragraph text.

Observation: All combining characters are included in the selections shown in fig_drop_caps.

Any punctuation such as opening quotes and opening parentheses should also be included in the initial styling. ?

Examples of dropped highlights — Two example paragraphs showing dropped highlighted initials with combining characters.

Observation: In the figures shown, the alphabetic baseline of the highlighted letter falls slightly below the bottom of the row that determines the size of the highlighted letter. It's not clear whether that's a general trend, or just related to this specific publication.

Observation: In fig_drop_caps_2, the selection picks out only แ from the syllable แฉ.

	Labial	Dental	Alveolar	Palatal	Velar	Glottal
Stop	p pʰ b	t tʰ d			k kʰ	ʔ
Affricate			tɕ tɕʰ
Fricative	f		s			h
Nasal	m		n		ŋ
Approximant	w		l	j
Trill/flap			r

	Labial	Dental	Alveolar	Palatal	Velar	Glottal
Stop	p	t			k	ʔ
Affricate
Fricative
Nasal	m		n		ŋ
Approximant	w			j
Trill/flap