Thai,[a] Central Thai[b] (historically Siamese;[c] : ภาษาไทย), is the national language of Thailand and de facto official language; it is the first language of the Central Thai people[d] and most Thai Chinese, depending on age. It is a member of the Tai group of the Kra–Dai language family, and one of over 60 languages of Thailand. Over half of Thai vocabulary is derived from or borrowed from Pali, Sanskrit, Mon and Old Khmer. It is a tonal and analytic language, similar to Chinese and Vietnamese.
Thai has a complex orthography and system of relational markers. Spoken Thai, depending on standard sociolinguistic factors such as age, gender, class, spatial proximity, and the urban/rural divide, is partly mutually intelligible with Lao, Isan, and some fellow Southwestern Tai languages. These languages are written with slightly different scripts but are linguistically similar and effectively form a dialect continuum.
The Thai language is classified as a Tai language, closely related to other Southwestern Tai languages including Lao, Shan in Myanmar, and numerous indigenous languages spoken in an arc from Hainan and Yunnan south through Laos and Northern Vietnam to the Cambodian border. It is the principal language of education and government and spoken throughout the country. The standard is based on the dialect of the central Thai people, and it is written in the Thai alphabet.
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 which 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:
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:
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/.
Note that 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.
Thai descends from proto-Tai-Kadai, which has been hypothesized to originate in the Lower Yangtze valleys. Ancient Chinese texts refer to non-Sinitic languages spoken cross this substantial region and their speakers as "Yue". Although those languages are extinct, traces of their existence could be found in unearthed inscriptional materials, ancient Chinese historical texts and non-Han substrata in various Southern Chinese dialects. Thai, as the most-spoken language in the Tai-Kadai language family, has been used extensively in historical-comparative linguistics to identify the origins of language(s) spoken in the ancient region of South China. One of the very few direct records of non-Sinitic speech in pre-Qin and Han times having been preserved so far is the "Song of the Yue Boatman" (Yueren Ge 越人歌), which was transcribed phonetically in Chinese characters in 528 BC, and found in the 善说 Shanshuo chapter of the Shuoyuan 说苑 or 'Garden of Persuasions'. In the early 80's the Zhuang linguist Wei Qingwen using reconstructed Old Chinese for the characters discovered that the resulting vocabulary showed strong resemblance to modern Zhuang. Later, Zhengzhang Shangfang (1991) followed Wei's insight but used Thai script for comparison, since this orthography dates from the 13th century and preserves archaisms vis-à-vis the modern pronunciation. The following is a simplified interpretation of the "Song of the Yue Boatman" by Zhengzhang Shangfang quoted by David Holm (2013) with Thai script and Chinese glosses being omitted. The upper row represents the original text, the next row the Old Chinese pronunciation, the third a transcription of written Thai, and the fourth line English glosses. Finally, there is Zhengzhang's English translation.
Besides this classical case, various papers in historical linguistics have employed Thai for comparative purposes in studying the linguistic landscape of the ancient region of Southern China. Proto-reconstructions of some scattered non-Sinitic words found in the two ancient Chinese fictional texts, Mu tianzi zhuan 穆天子傳 (4th c. B.C.) and Yuejue shu 越絕書 (1st c. A.D.), are used to compare to Thai/Siamese and its related languages in Tai-Kadai language family in an attempt to identify the origins of those words. The following examples are cited from Wolfgang Behr's work (2002):
"The Wú say yī for 'good' and huăn for 'way', i.e. in their titles they follow the central kingdoms, but in their names they follow their own lords."
伊 yī < MC ʔjij < OC *bq(l)ij ← Siamese diiA1, Longzhou dai1, Bo'ai nii1 Daiya li1, Sipsongpanna di1, Dehong li6 < proto-Tai *ʔdɛiA1 | Sui ʔdaai1, Kam laai1, Maonan ʔdaai1, Mak ʔdaai6 < proto-Kam-Sui/proto-Kam-Tai *ʔdaai1 'good'
缓 [huăn] < MC hwanX < OC *awan ← Siamese honA1, Bo'ai hɔn1, Dioi thon1 < proto-Tai *xronA1| Sui khwən1-i, Kam khwən1, Maonan khun1-i, Mulam khwən1-i < proto-Kam-Sui *khwən1 'road, way' | proto-Hlai *kuun1 || proto-Austronesian *Zalan (Thurgood 1994:353)
"The Middle mountains of Gū are the mountains of the Yuè's bronze office, the Yuè people call them 'Bronze gū[gū]dú'."
← Siamese kʰauA1 'horn', Daiya xau5, Sipsongpanna xau1, Dehong xau1, Lü xău1, Dioi kaou1 'mountain, hill' < proto-Tai *kʰauA2; Siamese luukD2l 'classifier for mountains', Siamese kʰauA1-luukD2l 'mountain' || cf. OC 谷 gǔ < kuwk << *ak-lok/luwk < *akə-lok/yowk < *blok 'valley'
"[Líu] Jiă (the king of Jīng 荆) built the western wall, it was called dìngcuò ['settle(d)' & 'grindstone'] wall."
? ← Siamese tokD1s 'to set→sunset→west' (tawan-tok 'sun-set' = 'west'); Longzhou tuk7, Bo'ai tɔk7, Daiya tok7, Sipsongpanna tok7 < proto-Tai *tokD1s ǀ Sui tok7, Mak tok7, Maonan tɔk < proto-Kam-Sui *tɔkD1
According to Ethnologue, Thai language is spoken by over 20 million people (2000). Moreover, most Thais in the northern and the northeastern (Isaan) parts of the country today are bilingual speakers of Central Thai and their respective regional dialects due to the fact that (Central) Thai is the language of television, education, news reporting, and all forms of media. A recent research found that the speakers of the Northern Thai language (or Kham Mueang) have become so few, as most people in northern Thailand now invariably speak Standard Thai, so that they are now using mostly Central Thai words and seasoning their speech only with "kham mueang" accent. Standard Thai is based on the register of the educated classes in Bangkok. In addition to Central Thai, Thailand is home to other related Tai languages. Although some linguists classify these dialects as related but distinct languages, native speakers often identify them as regional variants or dialects of the "same" Thai language, or as "different kinds of Thai".
Central Thai is composed of several distinct registers, forms for different social contexts:
Most Thais can speak and understand all of these contexts. Street and Elegant Thai are the basis of all conversations. Rhetorical, religious, and royal Thai are taught in schools as part of the national curriculum.
Thai is written in the Thai script, an abugida written from left to right. Many scholars believe that it is derived from the Khmer script. Certainly the numbers were lifted directly from Khmer. 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:
There is no universally applied method for transcribing Thai into the Latin alphabet. For example, the name of the main airport is transcribed variously as Suvarnabhumi, Suwannaphum, or Suwunnapoom. Guide books, textbooks and dictionaries may each follow different systems. For this reason, most language courses recommend that learners master the Thai script.
Official standards are the Royal Thai General System of Transcription (RTGS), published by the Royal Institute of Thailand, 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. 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 2003 (ISO 11940). 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.
Standard Thai distinguishes three voice-onset times among plosive and affricate consonants:
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 an alveolar /d/, /t/, /tʰ/ triplet in Thai. In the velar series there is a /k/, /kʰ/ pair and in the postalveolar series a /t͡ɕ/, /t͡ɕʰ/ 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 /t͡ɕ/.)
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 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.* The glottal plosive appears at the end when no final follows a short vowel
In Thai, each syllable in a word is considered separate from the others, so combinations of consonants from adjacent syllables are never recognised as a cluster. Thai has phonotactical constraints that define permissible syllable structure, consonant clusters, and vowel sequences. Original Thai vocabulary introduces only 11 combined consonantal patterns:
The number of clusters increases when a few more combinations are presented in loanwords such as /tʰr/ (ทร) in อินทรา (/intʰraː/, from Sanskrit indrā) or /fr/ (ฟร) in ฟรี (/friː/, from English free); however, it can be observed that Thai language supports only those 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 alphabet, where a dash (–) indicates the position of the initial consonant after which the vowel is pronounced. A second dash indicates that a final consonant must follow.
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".
There are also opening and closing diphthongs in Thai, which Tingsabadh & Abramson (1993) analyze as underlyingly /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, low, falling, high, and rising, sometimes referred to in older reference works as rectus, gravis, circumflexus, altus, and demissus, respectively. The table shows an example of both the phonemic tones and their phonetic realization, in the IPA.
In some English loanwords, closed syllables with long vowel ending in an obstruent sound, have high tone, and closed syllables with short vowel ending in an obstruent sound have falling tone.
From the perspective of linguistic typology, Thai can be considered to be an analytic language. The word order is subject–verb–object, although the subject is often omitted. 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.
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, [tʰùːk]) before the verb. For example:
To convey the opposite sense, a sense of having an opportunity arrive, ได้ (dai, [dâj], can) is used. For example:
Note, dai ([dâj] and [dâːj]), though both spelled ได้, convey two separate meanings. The short vowel dai ([dâj]) conveys an opportunity has arisen and is placed before the verb. The long vowel dai ([dâːj]) 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.
Thai exhibits serial verb constructions, where verbs are strung together. Some word combinations are common and may be considered set phrases.
Nouns are neither singular nor plural. 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 raw], 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, with nicknames used where English would use a pronoun. See informal and formal names 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 those with royal and noble titles, and for clergy. 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:
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 tone) when the speaker is male, and ค่ะ (kha, [kʰâ], with a falling tone) when the speaker is female. Used in a question or a request, the particle ค่ะ (falling tone) is changed to a คะ (high tone).
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:
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.
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. Old Khmer has also contributed its share, especially in regard to royal court terminology. 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.
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 practice 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.