Thai (ภาษาไทย, , transcription: phasa thai, transliteration: ; pʰāːsǎːtʰāj), is the national and official language of Thailand and the mother tongue of the Thai people, Thailand's dominant ethnic group. Thai is a member of the Tai group of the Tai-Kadai language family. The Tai-Kadai languages are thought to have originated in what is now southern China, and some linguists have proposed links to the Austroasiatic, Austronesian, or Sino-Tibetan language families. It is a tonal and analytic language. The combination of tonality, a complex orthography, relational markers and a distinctive phonology can make Thai difficult to learn for those who do not already speak a related language. Thai is mutual intelligible to Lao.
In addition to Standard Thai, Thailand is home to other related Tai languages, including:
Statistics are from Ethnologue 2003-10-4
Many of these languages are spoken by larger numbers outside of Thailand. Most speakers of dialects and minority languages speak Central Thai as well, since it is the language used in schools and universities all across the kingdom.
Numerous languages not related to Thai are spoken within Thailand by ethnic minority hill tribespeople. These languages include Hmong-Mien (Yao), Karen, Lisu, and others.
Standard Thai is composed of several distinct registers, forms for different social contexts:
Most of the Thais can speak and understand all of these contexts. Street and Elegant are the basis of all conversations, rhetorical, religious and royal Thai are taught in schools as the national curriculum has set so.
The Thai alphabet is derived from the Khmer alphabet, which is modeled after the Brahmic script from the Indic family. The language and its alphabet are closely related to the Lao language and alphabet. Most Laotians 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. Much like the Burmese adopted the Mon script (which also has Indic origins), the Thais adopted and modified Khmer script to create their own writing system. 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:
There is no universal standard for transcribing Thai into the Latin alphabet. For example, the name of King Rama IX, the present monarch, is transcribed variously as Bhumibol, Phumiphon, phuuM miH phohnM, or many other versions. Guide books, text books and dictionaries may each follow different systems. For this reason, most language courses recommend that learners master the Thai alphabet.
What comes closest to a standard is the Royal Thai General System of Transcription (RTGS), published by the Thai Royal Institute only in Thai at
This system is increasingly used in Thailand by central and local governments, especially for road signs. Its main drawbacks are that it does not indicate tone or vowel length. It is not possible to reconstruct the Thai spelling from the RTGS transcriptions.
The ISO published an international standard for the transliteration of Thai into Roman script in September 2003 (ISO 11940)
By adding diacritics to the Latin letters, it makes the transcription reversible, making it a true transliteration. This system is intended for academic use and is hardly ever used in Thailand for the common public.
Comparatives take the form "A X กว่า B" (kwa, kwaː), A is more X than B. The superlative is expressed as "A X ที่สุด" (thi sut, tʰiːsut), A is most X.
Because adjectives can be used as complete predicates, many words used to indicate tense in verbs (see Verbs:Tense below) may be used to describe adjectives.
The passive voice is indicated by the insertion of ถูก (thuk, tʰuːk)) before the verb. For example:
To convey the opposite sense, a sense of having an opportunity arrive, ได้ (dai, daj, can) is used. For example:
Note, dai (daj and daːj), though both spelled ได้ , convey two separate meanings. The short vowel dai (daj) conveys an opportunity has arisen and is placed before the verb. The long vowel dai (daːj) is placed after the verb and conveys the idea that one has been given permission or one has the ability to do something. Also see the past tense below.
Negation is indicated by placing ไม่ (mai, not) before the verb.
Tense is conveyed by tense markers before or after the verb.
Nouns are neither singular nor plural. Some specific nouns are reduplicated to form collectives: เด็ก (dek, child) is often repeated as เด็กๆ (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, , we, masculine; พวกเรา phuak rao, , 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 (ครูห้าคน, "teacher five person" for "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").
Subject pronouns are often omitted, while nicknames are often used where English would use a pronoun. There are specialised pronouns in the royal and sacred Thai languages. The following are appropriate for conversational use:
| Word | RTGS | IPA | Meaning |
|---|---|---|---|
| ผม | phom | [pʰǒm] | I/me (masculine; formal) |
| ดิฉัน | dichan | [dìːtɕʰán]) | I/me (feminine; formal) |
| ฉัน | chan | [tɕʰǎn] | I/me (masculine or feminine; informal) |
| คุณ | khun | [kʰun] | you (polite) |
| ท่าน | than | [tʰâːn] | you (polite to a person of high status) |
| เธอ | thoe | [tʰɤː] | you (informal), she/her (informal) |
| เรา | rao | [raw] | we/us, I/me (casual) |
| เขา | khao | [kʰǎw] | he/him, she/her |
| มัน | man | [mɑn] | it |
| พวกเขา | phuak khao | they/them | |
| พี่ | phi | [pʰîː] | older brother, sister (also often used loosely for older cousins and non-relatives) |
| น้อง | nong | [nɔːŋ] | younger brother, sister (also often used loosely for younger cousins and non-relatives) |
| ลูกพี่ ลูกน้อง | luk phi luk nong | cousin (male or female) |
Other common particles are:
| Word | RTGS | IPA | Meaning |
|---|---|---|---|
| จ๊ะ | cha | [tɕaʔ] | indicating a request |
| จ้ะ, จ้า or จ๋า | cha | [tɕaː] | indicating emphasis |
| ละ or ล่ะ | la | [laʔ] | indicating emphasis |
| สิ | si | [siʔ] | indicating emphasis or an imperative |
| นะ | na | [naʔ] | softening; indicating a request |
| Tone | Thai | Phonemic | Phonetic | English |
|---|---|---|---|---|
| mid | นา | /nāː/ | [naː˥˧] | a paddy |
| low | หน่า | /nàː/ | [naː˧˩] | (a nickname) |
| falling | หน้า | /nâː/ | [naː˥˩] | face |
| high | น้า | /náː/ | [naː˧˥] | aunt/uncle(younger than your parents) |
| rising | หนา | /nǎː/ | [naː˨˩˧] | thick |
Where English has only a distinction between the voiced, unaspirated /b/ and the unvoiced, aspirated /p/, Thai distinguishes a third sound which is neither voiced nor aspirated, which occurs in English only as an allophone of /p/, approximately the sound of the p in "spin." There is similarly an alveolar /t/, /tʰ/, /d/ triplet. In the velar series there is a /k/, /kʰ/ pair and in the postalveolar series the /tɕ/, /tɕʰ/ pair.
In each cell below, the first line indicates IPA (IPA), the second indicates the Thai characters in initial position (more letters appearing in the same box have identical pronunciation).
| Bilabial | Labio- dental | Alveolar | Post- alveolar | Palatal | Velar | Glottal | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nasal | ม | ณ,น | ง | |||||||||||
| Plosive | ป | ผ,พ,ภ | บ | ฏ,ต | ฐ,ฑ*,ฒ,ถ,ท,ธ | ฎ,ฑ*,ด | ก | ข,ฃ,ค,ฅ,ฆ | อ** | |||||
| Fricative | ฝ,ฟ | ซ,ศ,ษ,ส | ห,ฮ | |||||||||||
| Affricate | จ | ฉ, ช, ฌ | ||||||||||||
| Trill | ร | |||||||||||||
| Approximant | ญ,ย | ว | ||||||||||||
| Lateral approximant | ล,ฬ | |||||||||||||
| Front | Back | |||||
|---|---|---|---|---|---|---|
| unrounded | unrounded | rounded | ||||
| short | long | short | long | short | long | |
| Close | /i/ -ิ | /iː/ -ี | /ɯ/ -ึ | /ɯː/ -ื | /u/ -ุ | /uː/ -ู |
| Close-mid | /e/ เ-ะ | /eː/ เ- | /ɤ/ เ-อะ | /ɤː/ เ-อ | /o/ โ-ะ | /oː/ โ- |
| Open-mid | /ɛ/ แ-ะ | /ɛː/ แ- | /ɔ/ เ-าะ | /ɔː/ -อ | ||
| Open | /a/ -ะ, -ั | /aː/ -า | ||||
The vowels each exist in long-short pairs: these are distinct phonemes forming unrelated words in Thai, but usually transliterated the same: เขา (khao) means he or she, while ขาว (khao) means white.
The long-short pairs are as follows:
| Long | Short | ||||||
|---|---|---|---|---|---|---|---|
| Thai | IPA | Gloss | Thai script | IPA | Gloss | ||
| –า | /aː/ | /fǎːn/ | 'to slice' | –ะ | /a/ | /fǎn/ | 'to dream' |
| –ี | /iː/ | /krìːt/ | 'to cut' | –ิ | /i/ | /krìt/ | 'dagger' |
| –ู | /uː/ | /sùːt/ | 'to inhale' | –ุ | /u/ | /sùt/ | 'rearmost' |
| เ– | /eː/ | /ʔēːn/ | 'to recline' | เ–ะ | /e/ | /ʔēn/ | 'ligament' |
| แ– | /ɛː/ | /pʰɛ́ː/ | 'to be defeated' | แ–ะ | /ɛ/ | /pʰɛ́ʔ/ | 'goat' |
| –ื | /ɯː/ | /kʰlɯ̂ːn/ | 'wave' | –ึ | /ɯ/ | /kʰɯ̂n/ | 'to go up' |
| เ–อ | /ɤː/ | /dɤ̄ːn/ | 'to walk' | เ–อะ | /ɤ/ | /ŋɤ̄n/ | 'silver' |
| โ– | /oː/ | /kʰôːn/ | 'to fell' | โ–ะ | /o/ | /kʰôn/ | 'thick (soup)' |
| –อ | /ɔː/ | /klɔːŋ/ | 'drum' | เ–าะ | /ɔ/ | /klɔ̀ŋ/ | 'box' |
The basic vowels can be combined into diphthongs. analyze those ending in high vocoids as underlyingly /Vj/ and /Vw/. For purposes of determining tone, those marked with an asterisk are also classified as long:
| Long | Short | ||
|---|---|---|---|
| Thai | IPA | Thai | IPA |
| –าย | /aːj/ | ไ–*, ใ–*, ไ–ย | /aj/ |
| –าว | /aːw/ | เ–า* | /aw/ |
| เ–ีย | /iːa/ | เ–ียะ | /ia/ |
| – | – | –ิว | /iw/ |
| –ัว | /uːa/ | –ัวะ | /ua/ |
| –ูย | /uːj/ | –ุย | /uj/ |
| เ–ว | /eːw/ | เ–็ว | /ew/ |
| แ–ว | /ɛːw/ | – | – |
| เ–ือ | /ɯːa/ | – | – |
| เ–ย | /ɤːj/ | – | – |
| –อย | /ɔːj/ | – | – |
| โ–ย | /oːj/ | – | – |
Additionally, there are three triphthongs, all of which are long:
| Thai | IPA |
|---|---|
| เ–ียว | /iow/ |
| –วย | /uɛj/ |
| เ–ือย | /ɯɛj/ |
For a guide to written vowels, see the Thai alphabet page.
Thailand also uses the distinctive Thai six hour clock in addition to the 24 hour clock.