Thai language

Standard Thai is classified as one of the Chiang Saen languages—others being Northern Thai, Southern Thai and numerous smaller languages, which together with the Northwestern Tai and Lao-Phutai languages, form the Southwestern branch of Tai languages. The Tai languages are a branch of the Kra–Dai language family, which encompasses a large number of indigenous languages spoken in an arc from Hainan and Guangxi south through Laos and Northern Vietnam to the Cambodian border.

Standard Thai is the principal language of education and government and spoken throughout Thailand. The standard is based on the dialect of the central Thai people, and it is written in the Thai script.

Thai has undergone various historical sound changes. Some of the most significant changes occurred during the evolution from Old Thai to modern Thai. The Thai writing system has an eight-century history and many of these changes, especially in consonants and tones, are evidenced in the modern orthography.

Old Thai had a three-way tone distinction on "live syllables" (those not ending in a stop), with no possible distinction on "dead syllables" (those ending in a stop, i.e. either /p/, /t/, /k/ or the glottal stop that automatically closes syllables otherwise ending in a short vowel).

There was a two-way voiced vs. voiceless distinction among all fricative and sonorant consonants, and up to a four-way distinction among stops and affricates. The maximal four-way occurred in labials (/p pʰ b ʔb/) and dentals (/t tʰ d ʔd/); the three-way distinction among velars (/k kʰ ɡ/) and palatals (/tɕ tɕʰ dʑ/), with the glottalized member of each set apparently missing.

The major change between old and modern Thai was due to voicing distinction losses and the concomitant tone split. This may have happened between about 1300 and 1600 CE, possibly occurring at different times in different parts of the Thai-speaking area. All voiced–voiceless pairs of consonants lost the voicing distinction:

• Plain voiced stops (/b d ɡ dʑ/) became voiceless aspirated stops (/pʰ tʰ kʰ tɕʰ/).^[e]
• Voiced fricatives became voiceless.
• Voiceless sonorants became voiced.

However, in the process of these mergers, the former distinction of voice was transferred into a new set of tonal distinctions. In essence, every tone in Old Thai split into two new tones, with a lower-pitched tone corresponding to a syllable that formerly began with a voiced consonant, and a higher-pitched tone corresponding to a syllable that formerly began with a voiceless consonant (including glottalized stops). An additional complication is that formerly voiceless unaspirated stops/affricates (original /p t k tɕ ʔb ʔd/) also caused original tone 1 to lower, but had no such effect on original tones 2 or 3.

The above consonant mergers and tone splits account for the complex relationship between spelling and sound in modern Thai. Modern "low"-class consonants were voiced in Old Thai, and the terminology "low" reflects the lower tone variants that resulted. Modern "mid"-class consonants were voiceless unaspirated stops or affricates in Old Thai—precisely the class that triggered lowering in original tone 1 but not tones 2 or 3. Modern "high"-class consonants were the remaining voiceless consonants in Old Thai (voiceless fricatives, voiceless sonorants, voiceless aspirated stops). The three most common tone "marks" (the lack of any tone mark, as well as the two marks termed mai ek and mai tho) represent the three tones of Old Thai, and the complex relationship between tone mark and actual tone is due to the various tonal changes since then. Since the tone split, the tones have changed in actual representation to the point that the former relationship between lower and higher tonal variants has been completely obscured. Furthermore, the six tones that resulted after the three tones of Old Thai were split have since merged into five in standard Thai, with the lower variant of former tone 2 merging with the higher variant of former tone 3, becoming the modern "falling" tone.^[f]

Early Old Thai also apparently had velar fricatives /x ɣ/ as distinct phonemes. These were represented by the now-obsolete letters ฃ kho khuat and ฅ kho khon, respectively. During the Old Thai period, these sounds merged into the corresponding stops /kʰ ɡ/, and as a result the use of these letters became unstable.

At some point in the history of Thai, a palatal nasal phoneme /ɲ/ also existed, inherited from Proto-Tai. A letter ญ yo ying also exists, which is used to represent a palatal nasal in words borrowed from Sanskrit and Pali, and is currently pronounced /j/ at the beginning of a syllable but /n/ at the end of a syllable. Most native Thai words that are reconstructed as beginning with /ɲ/ are also pronounced /j/ in modern Thai, but generally spelled with ย yo yak, which consistently represents /j/. This suggests that /ɲ/ > /j/ in native words occurred in the pre-literary period. It is unclear whether Sanskrit and Pali words beginning with /ɲ/ were borrowed directly with a /j/, or whether a /ɲ/ was re-introduced, followed by a second change /ɲ/ > /j/.

Proto-Tai also had a glottalized palatal sound, reconstructed as /ʔj/ in Li Fang-Kuei (1977^{[full citation needed]}). Corresponding Thai words are generally spelled หย, which implies an Old Thai pronunciation of /hj/ (or/j̊/), but a few such words are spelled อย, which implies a pronunciation of /ʔj/ and suggests that the glottalization may have persisted through to the early literary period.

The vowel system of modern Thai contains nine pure vowels and three centering diphthongs, each of which can occur short or long. According to Li (1977^{[full citation needed]}), however, many Thai dialects have only one such short–long pair (/a aː/), and in general it is difficult or impossible to find minimal short–long pairs in Thai that involve vowels other than /a/ and where both members have frequent correspondences throughout the Tai languages. More specifically, he notes the following facts about Thai:

• Inopen syllables, only long vowels occur. (This assumes that all apparent cases of short open syllables are better described as ending in a glottal stop. This makes sense from the lack of tonal distinctions in such syllables, and the glottal stop is also reconstructible across the Tai languages.)
• Inclosed syllables, the long high vowels /iː ɯː uː/ are rare, and cases that do exist typically have diphthongs in other Tai languages.
• In closed syllables, both short and long mid /e eː o oː/ and low /ɛ ɛː ɔ ɔː/ do occur. However, generally, only words with short /e o/ and long /ɛː ɔː/ are reconstructible back to Proto-Tai.
• Both of the mid back unrounded vowels /ɤ ɤː/ are rare, and words with such sounds generally cannot be reconstructed back to Proto-Tai.

Furthermore, the vowel that corresponds to short Thai /a/ has a different and often higher quality in many of the Tai languages compared with the vowel corresponding to Thai /aː/.

This leads Li to posit the following:

1. Proto-Tai had a system of nine pure vowels with no length distinction, and possessing approximately the same qualities as in modern Thai: high /i ɯ u/, mid /e ɤ o/, low /ɛ a ɔ/.
2. All Proto-Tai vowels were lengthened in open syllables, and low vowels were also lengthened in closed syllables.
3. Modern Thai largely preserved the original lengths and qualities, but lowered /ɤ/to/a/, which became short /a/ in closed syllables and created a phonemic length distinction /a aː/. Eventually, length in all other vowels became phonemic as well and a new /ɤ/ (both short and long) was introduced, through a combination of borrowing and sound change. Li believes that the development of long /iː ɯː uː/ from diphthongs, and the lowering of /ɤ/to/a/ to create a length distinction /a aː/, had occurred by the time of Proto-Southwestern-Tai, but the other missing modern Thai vowels had not yet developed.

Not all researchers agree with Li. Pittayaporn (2009^{[full citation needed]}), for example, reconstructs a similar system for Proto-Southwestern-Tai, but believes that there was also a mid back unrounded vowel /ə/ (which he describes as /ɤ/), occurring only before final velar /k ŋ/. He also seems to believe that the Proto-Southwestern-Tai vowel length distinctions can be reconstructed back to similar distinctions in Proto-Tai.

Standard Thai distinguishes three voice-onset times among plosive and affricate consonants:

• voiced
• tenuis (unvoiced, unaspirated)
• aspirated

Where English makes a distinction between voiced /b/ and unvoiced aspirated /pʰ/, Thai distinguishes a third sound – the unvoiced, unaspirated /p/ that occurs in English only as an allophone of /pʰ/, for example after an /s/ as in the sound of the p in "spin". There is similarly a laminal denti-alveolar^{[citation needed]} /d/, /t/, /tʰ/ triplet in Thai. In the velar series there is a /k/, /kʰ/ pair and in the postalveolar series a /tɕ/, /tɕʰ/ pair, but the language lacks the corresponding voiced sounds /ɡ/ and /dʑ/. (In loanwords from English, English /ɡ/ and /d͡ʒ/ are borrowed as the tenuis stops /k/ and /tɕ/.)

In each cell below, the first line indicates International Phonetic Alphabet (IPA), the second indicates the Thai characters in initial position (several letters appearing in the same box have identical pronunciation). The letter ห, one of the two h letters, is also used to help write certain tones (described below).

Although the overall 44 Thai consonant letters provide 21 sounds in case of initials, the case for finals is different. For finals, only eight sounds, as well as no sound, called mātrā (มาตรา) are used. To demonstrate, at the end of a syllable, บ (/b/) and ด (/d/) are devoiced, becoming pronounced as /p/ and /t/ respectively. Additionally, all plosive sounds (besides the glottal stop /ʔ/) are unreleased. Hence, final /p/, /t/, and /k/ sounds are pronounced as [p̚], [t̚], and [k̚] respectively.

Of the consonant letters, excluding the disused ฃ and ฅ, six (ฉ ผ ฝ ห อ ฮ) cannot be used as a final and the other 36 are grouped as following.

In Thai, each syllable in a word is articulated independently, so consonants from adjacent syllables (i.e. heterosyllabic) show no sign of articulation as a cluster. Thai has specific phonotactical patterns that describe its syllable structure, including tautosyllabic consonant clusters, and vowel sequences. In core Thai words (i.e. excluding loanwords), only clusters of two consonants occur, of which there are 11 combinations:

• /kr/ (กร), /kl/ (กล), /kw/ (กว)
• /kʰr/ (ขร, คร), /kʰl/ (ขล, คล), /kʰw/ (ขว, คว)
• /pr/ (ปร), /pl/ (ปล)
• /pʰr/ (พร), /pʰl/ (ผล, พล)
• /tr/ (ตร)

The number of clusters increases in loanwords such as /tʰr/ (ทร) in อินทรา (/ʔīn.tʰrāː/, from Sanskrit indrā) or /fr/ (ฟร) in ฟรี (/frīː/, from English free); however, these usually only occur in initial position, with either /r/, /l/, or /w/ as the second consonant sound and not more than two sounds at a time.

The vowel nuclei of the Thai language are given in the following table. The top entry in every cell is the symbol from the International Phonetic Alphabet, the second entry gives the spelling in the Thai script, where a dash (–) indicates the position of the initial consonant after which the vowel is pronounced. A second dash indicates that a final consonant follows.

Each vowel quality occurs in long-short pairs: these are distinct phonemes forming distinct words in Thai.^[13]

The long-short pairs are as follows:

There are also opening and closing diphthongs in Thai, which Tingsabadh & Abramson (1993) analyze as /Vj/ and /Vw/. For purposes of determining tone, those marked with an asterisk are sometimes classified as long:

Additionally, there are three triphthongs. For purposes of determining tone, those marked with an asterisk are sometimes classified as long:

There are five phonemic tones: mid, falling, high, rising, and low-rising, sometimes referred to in older reference works as rectus, gravis, circumflexus, altus, and demissus, respectively.^[14] The table shows an example of both the phonemic tones and their phonetic realization, in the IPA. Moren & Zsiga (2006)^[15] and Zsiga & Nitisaroj (2007)^[16] provide phonetic and phonological analyses of Thai tone realization.

Notes:

1. Five-level tone value: Mid-level [33], Low-falling [21], High-falling [41], High-rising [45], Low-rising [24]. Traditionally, the high tone was recorded as either [44] or [45]. This remains true for the older generation, but the high tone is changing to [334] among youngsters.^[17][18]
2. For the diachronic changes of tone value, please see Pittayaporn (2007).^[19]
3. The full complement of tones exists only in so-called "live syllables", those that end in a long vowel or a sonorant (/m/, /n/, /ŋ/, /j/, /w/).
4. For "dead syllables", those that end in a plosive (/p/, /t/, /k/) or in a short vowel, only three tonal distinctions are possible: low, high, and falling. Because syllables analyzed as ending in a short vowel may have a final glottal stop (especially in slower speech), all "dead syllables" are phonetically checked, and have the reduced tonal inventory characteristic of checked syllables.

In some English loanwords, closed syllables with a long vowel ending in an obstruent sound have a high tone, and closed syllables with a short vowel ending in an obstruent sound have a falling tone.

From the perspective of linguistic typology, Thai can be considered to be an analytic language. The word orderissubject–verb–object,^[20] although the subject is often omitted. Additionally, Thai is an isolating language lacking any form of inflectional morphology whatsoever.^[21] Thai pronouns are selected according to the gender and relative status of speaker and audience.

There is no morphological distinction between adverbs and adjectives. Many words can be used in either function. They follow the word they modify, which may be a noun, verb, or another adjective or adverb.

khon

/kʰōn

อ้วน

uan

ʔûan/

คน อ้วน

khon uan

/kʰōn ʔûan/

'a fat person'

khon

/khōn

ที่

thi

tʰîː

อ้วน

uan

ʔûan

เร็ว

reo

rēw/

คน ที่ อ้วน เร็ว

khon thi uan reo

/khōn tʰîː ʔûan rēw/

'a person who became fat quickly'

Comparatives take the form "A X กว่า B" (kwa, /kwàː/), 'A is more X than B'. The superlative is expressed as "A X ที่สุด" (thi sut, /tʰîː sùt/), 'A is most X'.

khao

/kʰǎw

อ้วน

uan

ʔûan

กว่า

kwa

kwàː

ฉัน

chan

tɕʰǎn/

เขา อ้วน กว่า ฉัน

khao uan kwa chan

/kʰǎw ʔûan kwàː tɕʰǎn/

'S/he is fatter than me.'

khao

/kʰǎw

อ้วน

uan

ʔûan

ที่สุด

thi sut

tʰîː sùt/

เขา อ้วน ที่สุด

khao uan {thi sut}

/kʰǎw ʔûan tʰîː sùt/

'S/he is the fattest (of all).'

Adjectives in Thai can be used as complete predicates. Because of this, many words used to indicate tense in verbs (see Verbs:Tense below) may be used to describe adjectives.

chan

/tɕʰǎn

หิว

hio

hǐw/

ฉัน หิว

chan hio

/tɕʰǎn hǐw/

'I am hungry.'

chan

/tɕʰǎn

จะ

cha

tɕàʔ

หิว

hio

hǐw/

ฉัน จะ หิว

chan cha hio

/tɕʰǎn tɕàʔ hǐw/

'I will be hungry.'

chan

/tɕʰǎn

กำลัง

kamlang

kām.lāŋ

หิว

hio

hǐw/

ฉัน กำลัง หิว

chan kamlang hio

/tɕʰǎn kām.lāŋ hǐw/

'I am hungry right now.'

chan

/tɕʰǎn

หิว

hio

hǐw

แล้ว

laeo

lɛ́ːw/

ฉัน หิว แล้ว

chan hio laeo

/tɕʰǎn hǐw lɛ́ːw/

'I am already hungry.'

• Remark ฉันหิวแล้ว mostly means 'I am hungry right now' because normally, แล้ว (/lɛ́ːw/) marks the change of a state, but แล้ว has many other uses as well. For example, in the sentence, แล้วเธอจะไปไหน (/lɛ́ːw tʰɤ̄ː tɕàʔ pāj nǎj/): 'So where are you going?', แล้ว (/lɛ́ːw/) is used as a discourse particle.

Verbs do not inflect. They do not change with person, tense, voice, mood, or number; nor are there any participles. The language being analytic and case-less, the relationship between subject, direct and indirect object is conveyed through word order and auxiliary verbs. Transitive verbs follow the pattern subject-verb-object.

chan

/tɕʰǎn

1SG

ตี

ti

tīː

hit

เขา

khao

kʰǎw/

3SG

ฉัน ตี เขา

chan ti khao

/tɕʰǎn tīː kʰǎw/

1SG hit 3SG

'I hit him.'

khao

/kʰǎw

3SG

ตี

ti

tīː

hit

ฉัน

chan

tɕʰǎn/

1SG

เขา ตี ฉัน

khao ti chan

/kʰǎw tīː tɕʰǎn/

3SG hit 1SG

'S/He hit me.'

In order to convey tense, aspect and mood (TAM), the Thai verbal system employs auxiliaries and verb serialization.^[22][21] TAM markers are however not obligatory and often left out in colloquial use. In such cases, the precise meaning is determined through context.^[22] This results in sentences lacking both TAM markers and overt context being ambiguous and subject to various interpretations.

chan

/tɕʰǎn

กิน

kin

kīn

ที่

thi

tʰîː

นั่น

nan

nân/

ฉัน กิน ที่ นั่น

chan kin thi nan

/tɕʰǎn kīn tʰîː nân/

'I eat there.'

chan

/tɕǎn

กิน

kin

kīn

ที่

thi

tʰîː

นั่น

nan

nân

เมื่อวาน

mueawan

mɯ̂a.wāːn/

ฉัน กิน ที่ นั่น เมื่อวาน

chan kin thi nan mueawan

/tɕǎn kīn tʰîː nân mɯ̂a.wāːn/

'I ate there yesterday.'

chan

/tɕǎn

จะ

cha

tɕàʔ

กิน

kin

kīn

ที่

thi

thîː

นั่น

nan

nân

พรุ่งนี้

phrungni

pʰrûŋ.níː/

ฉัน จะ กิน ที่ นั่น พรุ่งนี้

chan cha kin thi nan phrungni

/tɕǎn tɕàʔ kīn thîː nân pʰrûŋ.níː/

'I'll eat there tomorrow.'

The sentence chan kin thi nan can thus be interpreted as 'I am eating there', 'I eat there habitually', 'I will eat there' or 'I ate there'. Aspect markers in Thai have been divided into four distinct groups based on their usage.^[22] These markers could appear either before or after the verb. The following list describes some of the most commonly used aspect markers. A number of these aspect markers are also full verbs on their own and carry a distinct meaning. For example yu (อยู่) as a full verb means 'to stay, to live or to remain at'. However, as an auxiliary it can be described as a temporary aspectorcontinuative marker.^[22]

• Imperfective
  • อยู่ yu /jùː/
  • ไป pai /pāj/
  • ยัง yang /jāŋ/
  • กำลัง kamlang /kām.lāŋ/
• Perfective
  • ได้ dai /dâːj/
• Perfect
  • แล้ว laeo /lɛ́ːw/
  • มา ma /māː/
• Prospective/Future
  • จะ cha /tɕàʔ/

The imperfective aspect marker กำลัง (kamlang, /kām lāŋ/, currently) is used before the verb to denote an ongoing action (similar to the -ing suffix in English). Kamlang is commonly interpreted as a progressive aspect marker.^[23][24] Similarly, อยู่ (yu, /jùː/) is a post-verbal aspect marker which corresponds to the continuative or temporary aspect.^[22]

khao

/kʰǎw

กำลัง

kamlang

kām.lāŋ

วิ่ง

wing

wîŋ/

เขา กำลัง วิ่ง

khao kamlang wing

/kʰǎw kām.lāŋ wîŋ/

khao

/kʰǎw

วิ่ง

wing

wîŋ

อยู่

yu

jùː/

เขา วิ่ง อยู่

khao wing yu

/kʰǎw wîŋ jùː/

khao

/kʰǎw

กำลัง

kamlang

kām.lāŋ

วิ่ง

wing

wîŋ

อยู่

yu

jùː/

เขา กำลัง วิ่ง อยู่

khao kamlang wing yu

/kʰǎw kām.lāŋ wîŋ jùː/

'He is running.'

The marker ได้ (dai, /dâːj/) is usually analyzed as a past tense marker when it occurs before the verb.^[21] As a full verb, dai means 'to get or receive'. However, when used after a verb, dai takes on a meaning of potentiality or successful outcome of the main verb.^[22]

เขา

khao

/kʰǎw

ได้

dai

dâːj

ไป

pai

pāj

เที่ยว

thiao

tʰîaw

เมือง

mueang

mɯ̄aŋ

ลาว

lao

lāːw/

เขา ได้ ไป เที่ยว เมือง ลาว

khao dai pai thiao mueang lao

/kʰǎw dâːj pāj tʰîaw mɯ̄aŋ lāːw/

He visited Laos. (Past/Perfective)

เขา

khao

/kʰǎw

3SG

ตี

ti

tīː

hit

ได้

dai

dâːj/

POT

เขา ตี ได้

khao ti dai

/kʰǎw tīː dâːj/

3SG hit POT

'He is/was allowed to hit' or 'He is/was able to hit.' (Potentiality)

แล้ว (laeo, /lɛ́ːw/; 'already') is treated as a marker indicating the perfect aspect.^[23] That is to say, laeo marks the event as being completed at the time of reference. Laeo has to other meanings in addition to its use as a TAM marker. Laeo can either be a conjunction for sequential actions or an archaic word for 'to finish'.

khao

/kʰǎw

3SG

ได้

dai

dâːj

PST

กิน

kin

kīn/

eat

เขา ได้ กิน

khao dai kin

/kʰǎw dâːj kīn/

3SG PST eat

He ate.

khao

/kʰǎw

3SG

กิน

kin

kīn

eat

แล้ว

laeo

lɛ́ːw/

PRF

เขา กิน แล้ว

khao kin laeo

/kʰǎw kīn lɛ́ːw/

3SG eat PRF

He has eaten.

khao

/kʰǎw

3SG

ได้

dai

dâːj

PST

กิน

kin

kīn

eat

แล้ว

laeo

lɛ́ːw/

PRF

เขา ได้ กิน แล้ว

khao dai kin laeo

/kʰǎw dâːj kīn lɛ́ːw/

3SG PST eat PRF

He's already eaten.

Future can be indicated by จะ (cha, /tɕàʔ/; 'will') before the verb or by a time expression indicating the future. For example:

เขา

khao

/kʰǎw

3SG

จะ

cha

tɕàʔ

FUT

วิ่ง

wing

wîŋ/

run

เขา จะ วิ่ง

khao cha wing

/kʰǎw tɕàʔ wîŋ/

3SG FUT run

'He will run' or 'He is going to run.'

The passive voice is indicated by the insertion of ถูก (thuk, /tʰùːk/) before the verb. For example:

เขา

khao

/kʰǎw

3SG

ถูก

thuk

tʰùːk

PASS

ตี

ti

tīː/

hit

เขา ถูก ตี

khao thukti

/kʰǎw tʰùːk tīː/

3SG PASS hit

'He got hit.'

This describes an action that is out of the receiver's control and, thus, conveys suffering.

Negation is indicated by placing ไม่ (mai, /mâj/; not) before the verb.

• เขาไม่ตี, (khao mai ti) 'He is not hitting' or 'He doesn't hit'.

Thai exhibits serial verb constructions, where verbs are strung together. Some word combinations are common and may be considered set phrases.

เขา

khao

/kʰǎw

he

ไป

pai

pāj

go

กิน

kin

kīn

eat

ข้าว

khao

kʰâːw/

rice

เขา ไป กิน ข้าว

khao pai kin khao

/kʰǎw pāj kīn kʰâːw/

he go eat rice

'He went out to eat'

ฉัน

chan

/tɕʰǎn

I

ฟัง

fang

fāŋ

listen

ไม่

mai

mâj

not

เข้าใจ

khao chai

kʰâw tɕāj/

understand

ฉัน ฟัง ไม่ เข้าใจ

chan fang mai {khao chai}

/tɕʰǎn fāŋ mâj kʰâw tɕāj/

I listen not understand

'I don't understand what was said'

เข้า

khao

/kʰâw

enter

มา

ma

māː/

come

เข้า มา

khao ma

/kʰâw māː/

enter come

'Come in'

ออก

ok

/ʔɔ̀ːk

exit

ไป!

pai

pāj/

go

ออก ไป!

ok pai

/ʔɔ̀ːk pāj/

exit go

'Leave!' or 'Get out!'

Nouns are uninflected and have no gender; there are no articles. Thai nouns are bare nouns and can be interpreted as singular, plural, definite or indefinite.^[25] Some specific nouns are reduplicated to form collectives: เด็ก (dek, 'child') is often repeated as เด็ก ๆ (dek dek) to refer to a group of children. The word พวก (phuak, /pʰûak/) may be used as a prefix of a noun or pronoun as a collective to pluralize or emphasise the following word. (พวกผม, phuak phom, /pʰûak pʰǒm/, 'we', masculine; พวกเรา phuak rao, /pʰûak rāw/, emphasised 'we'; พวกหมา phuak ma, '(the) dogs'). Plurals are expressed by adding classifiers, used as measure words (ลักษณนาม), in the form of noun-number-classifier:

khru

/kʰrūː

teacher

ห้า

ha

hâː

five

คน

khon

kʰōn/

person

ครู ห้า คน

khru ha khon

/kʰrūː hâː kʰōn/

teacher five person

"five teachers"

While in English, such classifiers are usually absent ("four chairs") or optional ("two bottles of beer" or "two beers"), a classifier is almost always used in Thai (hence "chair four item" and "beer two bottle").

Possession in Thai is indicated by adding the word ของ (khong) in front of the nounorpronoun, but it may often be omitted. For example:

luk

/lûːk

child

ของ

khong

kʰɔ̌ːŋ

belonging to

แม่

mae

mɛ̂ː/

mother

ลูก ของ แม่

luk khong mae

/lûːk kʰɔ̌ːŋ mɛ̂ː/

child {belonging to} mother

"mother's child"

na

/nāː

field

อา

a

ʔāː/

uncle

นา อา

na a

/nāː ʔāː/

field uncle

"uncle's field"^[26]

Nominal phrases in Thai often use a special class of words classifiers. As previously mentioned, these classifiers are obligatory for noun phrases containing numerals e.g.

phuying

/pʰûː.jǐŋ

woman

สอง

song

sɔ̌ːŋ

two

คน

khon

kʰōn/

CL

ผู้หญิง สอง คน

phuying song khon

/pʰûː.jǐŋ sɔ̌ːŋ kʰōn/

woman two CL

two women^[27]

In the previous example khon (คน) acts as the classifier in the nominal phrase. This follows the form of noun-cardinal-classifier mentioned above. Classifiers are also required to form quantified noun phrases in Thai with some quantifiers such as ทุก ('all'), บาง ('some'). The examples below are demonstrated using the classifier khon, which is used for people.

nak rian

/nák rīan

student

ทุก

thuk

tʰúk

every

คน

khon

kʰōn/

CL

{นักเรียน} ทุก คน

{nak rian} thuk khon

/nák rīan tʰúk kʰōn/

student every CL

"every student"

khru

/kʰrūː

teacher

บาง

bang

bāːŋ

some

คน

khon

kʰōn/

CL

ครู บาง คน

khru bang khon

/kʰrūː bāːŋ kʰōn/

teacher some CL

"some teacher"

However, classifiers are not utilized for negative quantification. Negative quantification is expressed by the pattern ไม่มี (mai mi, /mâj mīː/) + NOUN. Classifiers are also used for demonstratives such as นี้ (ni, /níː/; 'this/these') and นั่น (nan, /nán/; 'that/those'). The syntax for demonstrative phrases, however, differ from that of cardinals and follow the pattern noun-classifier-demonstrative. For example, the noun phrase "this dog" would be expressed in Thai as หมาตัวนี้ (literally 'dog (classifier) this').^[27]

Subject pronouns are often omitted, with nicknames used where English would use a pronoun. See Thai name#Nicknames for more details. Pronouns, when used, are ranked in honorific registers, and may also make a T–V distinction in relation to kinship and social status. Specialised pronouns are used for royalty, and for Buddhist monks. The following are appropriate for conversational use:

The reflexive pronoun is ตัวเอง (tua eng), which can mean any of: myself, yourself, ourselves, himself, herself, themselves. This can be mixed with another pronoun to create an intensive pronoun, such as ตัวผมเอง (tua phom eng, lit: I myself) or ตัวคุณเอง (tua khun eng, lit: you yourself). Thai also does not have a separate possessive pronoun. Instead, possession is indicated by the particle ของ (khong). For example, "my mother" is แม่ของผม (mae khong phom, lit: mother of I). This particle is often implicit, so the phrase is shortened to แม่ผม (mae phom). Plural pronouns can be easily constructed by adding the word พวก (phuak) in front of a singular pronoun as in พวกเขา (phuak khao) meaning 'they' or พวกเธอ (phuak thoe) meaning the plural sense of 'you'. The only exception to this is เรา (rao), which can be used as singular (informal) or plural, but can also be used in the form of พวกเรา (phuak rao), which is only plural.

Thai has many more pronouns than those listed above. Their usage is full of nuances. For example:

• "ผม เรา ฉัน ดิฉัน หนู กู ข้า กระผม ข้าพเจ้า กระหม่อม อาตมา กัน ข้าน้อย ข้าพระพุทธเจ้า อั๊ว เขา" all translate to "I", but each expresses a different gender, age, politeness, status, or relationship between speaker and listener.
• เรา (rao) can be first person (I), second person (you), or both (we), depending on the context.
• Children or younger female could use or being referred by word หนู (nu) when talking with older person. The word หนู could be both feminine first person (I) and feminine second person (you) and also neuter first and neuter second person for children.
  • หนู commonly means rat or mouse, though it also refers to small creatures in general.
• The second person pronoun เธอ (thoe) (lit: you) is semi-feminine. It is used only when the speaker or the listener (or both) are female. Males usually do not address each other by this pronoun.
• Both คุณ (khun) and เธอ (thoe) are polite neuter second person pronouns. However, คุณเธอ (khun thoe) is a feminine derogative third person.
• Instead of a second person pronoun such as คุณ ('you'), it is much more common for unrelated strangers to call each other พี่ น้อง ลุง ป้า น้า อา ตาorยาย (brother, sister, aunt, uncle, granny).
• To express deference, the second person pronoun is sometimes replaced by a profession, similar to how, in English, presiding judges are always addressed as "your honor" rather than "you". In Thai, students always address their teachers by ครู, คุณครูorอาจารย์ (each meaning 'teacher') rather than คุณ ('you'). Teachers, monks, and doctors are almost always addressed this way.

The particles are often untranslatable words added to the end of a sentence to indicate respect, a request, encouragement or other moods (similar to the use of intonation in English), as well as varying the level of formality. They are not used in elegant (written) Thai. The most common particles indicating respect are ครับ (khrap, /kʰráp/, with a high-rising tone) when the speaker is male, and ค่ะ (kha, /kʰâʔ/, with a low-falling tone) when the speaker is female. Used in a question or a request, the particle ค่ะ (low-falling tone) is changed to a คะ (high-rising tone).

Other common particles are:

Central Thai is composed of several distinct registers, forms for different social contexts:

• Street or Common Thai (ภาษาพูด, phasa phut, spoken Thai): informal, without polite terms of address, as used between close relatives and friends.
• Elegant or Formal Thai (ภาษาเขียน, phasa khian, written Thai): official and written version, includes respectful terms of address; used in simplified form in newspapers.
• Rhetorical Thai: used for public speaking.
• Religious Thai: (heavily influenced by Sanskrit and Pāli) used when discussing Buddhism or addressing monks.
• Royal Thai (ราชาศัพท์, racha sap): influenced by Khmer, this is used when addressing members of the royal family or describing their activities. (See Monarchy of Thailand § Rachasap.)

Most Thais can speak and understand all of these contexts. Street and Elegant Thai are the basis of all conversations.^{[31][citation needed]} Rhetorical, religious, and royal Thai are taught in schools as part of the national curriculum.

As noted above, Thai has several registers, each having certain usages, such as colloquial, formal, literary, and poetic. Thus, the word 'eat' can be กิน (kin; common), แดก (daek; vulgar), ยัด (yat; vulgar), บริโภค (boriphok; formal), รับประทาน (rapprathan; formal), ฉัน (chan; religious), or เสวย (sawoei; royal), as illustrated below:

Thailand also uses the distinctive Thai six-hour clock in addition to the 24-hour clock.

Other than compound words and words of foreign origin, most words are monosyllabic.

Chinese-language influence was strong until the 13th century when the use of Chinese characters was abandoned, and replaced by Sanskrit and Pali scripts. However, the vocabulary of Thai retains many words borrowed from Middle Chinese.^[32][33][34]

Khmer was used as a prestige language in the early days of the Thai kingdoms which are believed to have been bilingual societies proficient in Thai and Khmer. There are over 2,500 Thai words derived from Khmer, surpassing the number of Tai cognates. These Khmer words span across all semantic fields. Thai scholar Uraisi Varasarin classified them into over 200 sub-categories. As a result, it is impossible for Thais, past and present, to engage in a conversation without incorporating Khmer loanwords in any given topic. The influence is particularly preponderant in regard to royal court terminology. ^[35]

Later, most vocabulary was borrowed from Sanskrit and Pāli; Buddhist terminology is particularly indebted to these. Indic words have a more formal register, and may be compared to Latin and French borrowings in English. Since the beginning of the 20th century, however, the English language has had the greatest influence, especially for scientific, technical, international, and other modern terms.

From Middle ChineseorTeochew Chinese.

From Old Khmer

The Portuguese were the first Western nation to arrive in what is modern-day Thailand in the 16th century during the Ayutthaya period. Their influence in trade, especially weaponry, allowed them to establish a community just outside the capital and practise their faith, as well as exposing and converting the locals to Christianity. Thus, Portuguese words involving trade and religion were introduced and used by the locals.

Thai is written in the Thai script, an abugida written from left to right. The language and its script are closely related to the Lao language and script. Most literate Lao are able to read and understand Thai, as more than half of the Thai vocabulary, grammar, intonation, vowels and so forth are common with the Lao language.

The Thais adopted and modified the Khmer script to create their own writing system. While in Thai the pronunciation can largely be inferred from the script, the orthography is complex, with silent letters to preserve original spellings and many letters representing the same sound. While the oldest known inscription in the Khmer language dates from 611 CE, inscriptions in Thai writing began to appear around 1292 CE. Notable features include:

1. It is an abugida script, in which the implicit vowel is a short /a/ in a syllable without final consonant and a short /o/ in a syllable with final consonant.
2. Tone markers, if present, are placed above the final onset consonant of the syllable.
3. Vowels sounding after an initial consonant can be located before, after, above or below the consonant, or in a combination of these positions.

There is no universally applied method for transcribing Thai into the Latin alphabet. For example, the name of the main airport is transcribed variably as Suvarnabhumi, Suwannaphum, or Suwunnapoom. Guide books, textbooks and dictionaries may each follow different systems. For this reason, many language courses recommend that learners master the Thai script.^{[37][38][39][40]}

Official standards are the Royal Thai General System of Transcription (RTGS), published by the Royal Institute of Thailand,^[41] and the almost identical ISO 11940-2 defined by the International Organization for Standardization. The RTGS system is increasingly used in Thailand by central and local governments, especially for road signs.^[42] Its main drawbacks are that it does not indicate tone or vowel length. As the system is based on pronunciation, not orthography, reconstruction of Thai spelling from RTGS romanisation is not possible.

The ISO published an international standard for the transliteration of Thai into Roman script in September 2005 (ISO 11940).^[43] By adding diacritics to the Latin letters it makes the transcription reversible, making it a true transliteration. Notably, this system is used by Google Translate, although it does not seem to appear in many other contexts, such as textbooks and other instructional media.

• Thai script
• Thai honorifics
• Thai literature
• Thai numerals
• Thai braille
• Thai typography
• Comparison of Lao and Thai

• Inglis, Douglas. 1999. Lexical conceptual structure of numeral classifiers in Thai-Part 1. Payap Research and Development Institute and The Summer Institute of Linguistics. Payap University.
• Inglis, Douglas. 2000. Grammatical conceptual structure of numeral classifiers in Thai-Part 2. Payap Research and Development Institute and The Summer Institute of Linguistics. Payap University.
• Inglis, Douglas. 2003. Conceptual structure of numeral classifiers in Thai. In Eugene E. Casad and Gary B. Palmer (eds.). Cognitive linguistics and non-Indo-European languages. CLR Series 18. De Gruyter Mouton. 223–246. ISBN 978-311-017-371-0

• IPA and SAMPA for Thai
• Consonant Ear Training Tape
• Tones of Tai Dialect

Glossaries and word lists

• Thai phrasebook from Wikivoyage
• Thai Swadesh list of basic vocabulary words (from Wiktionary's Swadesh-list appendix)

Dictionaries

• English–Thai Dictionary: English–Thai bilingual online dictionary
• The Royal Institute Dictionary, official standard Thai–Thai dictionary
• Thai-English dictionary
• Thai2english.com: LEXiTRON-based Thai–English dictionary
• Daoulagad Thai: mobile OCR Thai–English dictionary
• Thai dictionaries for Stardict/GoldenDict – Thai – English (also French, German, Italian, Russian, Chinese and others) dictionaries in Stardict and GoldenDict formats
• Volubilis Dictionary VOLUBILIS (Romanized Thai – Thai – English – French): free databases (ods/xlsx) and dictionaries (PDF) – Thai transcription system.

Learners' resources

• thai-language.com English speakers' online resource for the Thai language
• Say Hello in the Thai Language
• FSI Thai language course (Formerly at thailanguagewiki.com)
• Spoken Thai (30 exercises with audio)