A Profile of the Thai Language

John Hartmann
Thomas John Hudak


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    Historical Overview. Thai (Siamese) is the official language of the Kingdom of Thailand. It is but one of many languages and dialects belonging to the historical or proto-Tai family, which is divided into three major branches: Northern Tai, Central Tai, and Southwestern Tai. Thai (Siamese) is in the third branch of the family, which also includes the Lao dialects of Laos, the Shan dialects of Upper Burma, several Tai dialects spoken in Yunnan Province in China, such as Tai Lue in the Sipsongpanna Region and Tai Dam, which originated in northwestern Vietnam but has now appeared greatly transformed in Laos and the U.S. -chiefly in Iowa- as part of the diaspora from the wars in Indochina.



Southwestern Central Northern
Thai S. Zhuang N. Zhuang
Lao Tho Saek
Shan Nung Bouyei
Black, White   Yay
& Red Tai   Mene

The Three Branches of the Tai Language Family

    Within Southwestern Tai there is a great deal of mutual intelligibility, these dialects sharing as much as 70% common lexicon. The most distinguishing feature of any dialect is tones - their number, shapes, and historical splits from the three tones of proto-Tai. The maximum number of possible phonemic tones is nine; seven is the highest number of tones within Thailand, namely the variety of Thai spoken in the South.
    Official or Standard Thai is based on the idealized speech of the educated elite of Bangkok and large portions of the Central Plain. The other main regional dialects are Northern Thai, spoken around Chiangmai; Northeastern Thai (Isan), spoken to the east of Korat; and Southern Thai, spoken south of Chumpon and into neighboring communities of northern Malaysia. The younger, educated population of these regions are bi-dialectal owing to the success of the central government's literacy programs. However, strong regional identity has served until recently to keep local dialects alive, even though Central Thai is on the ascendency. In Bangkok itself there are large communities of Chinese (Taechiew and Hailam, for example) who speak varieties of Sino-Thai, shaped by age, ethnic origins, education, and social mobility. Likewise, sizable communities of Lao and Isan speakers reside in Bangkok as new residents or seasonal laborers. Because Bangkok is a mosaic of diverse speech communities, it is difficult to generalize about the "language of the street" because so little fieldwork has been done on urban conversational Thai.
    Thailand has a population of over 60 million. Perhaps as many as half of these speak Central/Standard Thai at home, school, or business. The remaining half speak a regional dialect or a non-Tai language, such as Hmong or Lahu in the North, Lao or Khmer in the Northeast, and Malay in the South. In the U.S. there are large Thai communities, the largest of which is in the Los Angeles area. More modest settlements of largely professional Thais (doctors, nurses, engineers, restauranteurs) live in Chicago, New York, and Washington, D.C.

    Phonology. The Thai sound system is best described in relationship to the syllable, the tone-bearing unit. A Thai syllable has the maximum shape of C(C)V(V)(C)+Tone. There are five tones, which will be delineated later. There are twenty consonants in syllable-initial position, all easily pronounced by English speakers with the exception of the voiceless unaspirated series p- t- k- ʔ- (glottal stop). Initial consonant clusters include labials- pr, pl, phr, phl; alveolars- tr, thr (mostly literary); and velars- kr, kl, khr, khl, khw. Cluster simplification (pl > p, for example) is a fixed feature of dialects in the North and Northeast and in Laos, where tr > k also in some dialects. The most prominent sociolinguistic index is syllable-initial r~l variation. Only in the South is r- well-preserved. In Bangkok speech r- is maintained by the highly-educated and self-conscious and promoted by schools and the media. (One recent pop song has the title, "Where Has 'R' Gone To?") In varieties of Northern and Northeastern Thai and Lao the progressions is r>l>h. As for syllable-final consonants, only m, n, ng [ŋ], y, w, p, t, k and the glottal stop [ʔ] occur.
    There are nine vowels, long and short. Thus vowel length is phonemic: yaaŋ 'rubber' vs. yaŋ 'still, yet'. All but two of the vowels are fairly isomorphic with American English vowels, except for the high and mid back, unrounded "eu" and "er," which are often transcribed as ʉ and ə, respectively. There are three diphthongs composed of the three short and long vowels followed by a centering off-glide -a. In some dialects n the northern reaches of Southwestern Tai, the diphthongs become monothongs and are lowered from high to mid position.

    Tones. There are 5 phonemic tones on smooth syllables in Standard Thai, as follows:

    1.    Mid-level, with a slight fall in stressed or utterance-final position.
            khaa 'to be stuck'

    2.    Low-level.
            khàa 'galangal'

    3.    Falling from high to low, with glottalized voice quality. (This tone in particular, especially among females, has undergone striking change in Bangkok speech in the present generation. It now starts at a higher level, rises in the early part of the syllable to a peak and then falls to a point below mid-level.)
            khaˆa 'slave'

    4.    High-level/slight rise, glottalized.
            kháa 'to do business'

    5.    Rising from low to high.
         khăa 'leg'

    In isolation, tones 1 and 2 are perceptively close and are difficult to distinguish when context is absent. Tones are relatively "high, mid, low, falling, and rising", and differ with age and gender and sex-orientation. On checked syllables, tone is conditioned by vowel length and phonetic history of the initial consonant.

    Morphology. Thai is not inflected for case, gender, tense, or number. Time situations are dealt with separate morphemes, word order, and time words (today, last week, next year, for example). Number is likewise shown with separate numerals, quantifiers, and, when counting, classifiers.

    Derivatives are formed with a limited number of prefixes and suffixes. For example, the prefix khwaam 'the condition of', when combined with the class of verb/adjective produces abstract nouns expressing a state or quality, such as   khwaam-ciŋ 'truth'. Compounds include coordinate nouns, such as phɔˆɔ  mɛˆɛ 'parents' from phɔˆɔ 'father' and mɛˆɛ 'mother'; coordinate verbs, such as cʉˆa-faŋ 'to obey' from chʉˆa 'to believe' and faŋ 'to listen to'; and attributive compounds, such as rót-fay 'train' from rót 'vehicle, car' and fay 'fire'.

    Reduplication is productive and is of three types. Simple reduplication of a base form, such as dii 'good' to dii-dii 'rather good', which softens the meaning or pluralizes, as in dèk-dèk 'children' from dèk 'a child'. With a change of tone where the first tone is always higher in pitch, the significance is one of emphasis:  dií-dii 'really good!' Ablauting reduplication alternates a back vowel with a corresponding front vowel: soo-see 'to stagger'; or alternation of any vowel with /a/: chíʔ-cháʔ 'to hate, loathe'.

    Semantic doublets and elaborate expressions are a special type of compounding formed on the basis of sharing a certain degree of similarity. Examples are tháŋ-sín 'all' (adv.) from (adj.) tháŋ 'all' and sín 'all through' (prep.). In their most elaborate form, they have a poetic quality as in huŭ-pàa-taa-thʉ̀an 'ear-forest-eye-forest', which means 'to be ignorant of what is going on.'

    Syntax. Thai is an SVO (Subject+Verb+Object) language. It is also described with benefit as a Topic+Comment/Question language. A good deal of "grammaticality" is dictated by word order: maˆy daˆy pay '...didn't go' vs. pay maˆy daˆy '...cannot go'. 

    Nouns and verbs comprise the two largest classes of words in the lexicon. There is no clear-cut distinction between verbs and adjectives. Thus phɔˆɔ dii can be translated as 'Father is good' or 'the good father.' Noun substitutes include formal pronouns and -more commonly among family and friends- kin terms. Titles are also commonly used as noun substitutes: ʔaacaan 'professor'; khun mɔ̆ɔ 'doctor', for example. The choice of formal pronouns follow a hierarchy of power, with age and social position (money, title and education) and social setting being the chief determinants. The most socially neutral first person pronouns are the only ones that identify the sex of the speaker:  phŏm 'I-male' and dichăn 'I-female'. Thai is noted as a "pro-drop" language, both as a means of avoiding decisions about what pronoun to use and because the referent is understood from context, especially in face-to-face conversation. Pronouns have also been borrowed into Thai from Chinese and English. The English pronouns "I" and "You" are employed by Thai urbanites because they are socially neutral, exhibiting mild indifference. The historically older pronouns  kuu-mʉŋ 'I-You' are used chiefly by "buddies" to demonstrate bonding or, conversely, to heap invective on adversaries. The equivalent of the English 'it' is  man and is used to refer to animals, children, and outsiders, such as foreigners. The demonstrative pronouns niˆi, naˆn, noˆon 'this one, that one, yonder one', divides space into three degrees of proximity. A single form is used for the interrogative/indefinite pronoun: khray 'who/anybody or nobody'; thiˆi năy 'where/anywhere or nowhere', and so forth. Nouns+Attributes are simple  -luˆuk phŏm 'my child'- and complex -luˆuk săam khon 'three children' [Noun + Number + Classifier: offspring + 3 + person].

    Predicates. Subject is followed by the predicate. Time expression such as 'now/yesterday/next month' and preverbs, such as cà 'will' and daˆy 'got to do or did something' are separate morphemes. Thai is noted for long verbs strings, with up to seven in a single concatenation. Verbs are negated with the form maˆy + Verb . Modals such as 'must' tɔˆŋ 'probably' khoŋ 'likely to' are likewise preverbs. Postverbs include the forms way4 'to do something for later use' and daˆy 'can'.

    Utterance-Final Particles. Statements can be converted to questions with the addition of a final question particle, such as máy 'yes/no?' rʉ̆ʉ 'eh?/I assume?' Polite particles used to "speak upward" are initiated by the younger or socially less powerful to show deference; an "inferior" male will terminate his utterances (statements and questions) with the particle khráp and female subordinates will use  khá to terminate questions and   khaˆ for statements. These particles are also employed as a polite confirmation particle. A "semi-polite" variant is   há/haˆ. A number of "mood particles" are used where stress might be in English to show attitude toward a situation or listener:   rɔ̀ɔk corrects a misapprehension or refutes; náʔ asks for compliance or an indication of understanding.

    Complements include relative clauses headed by  thiˆi 'that/which'; causatives initiated by haˆy 'to make, let, have someone do something'; and the comparative- superlative  -kwàa 'more/-er' and thiˆi-sùt 'the most/-est'.

    The Lexicon and Problem Areas for Translators and Interpreters. Chief among the problems faced by even rather advanced students of Thai in dealing with both spoken and written Thai is the matter of who is speaking to whom or being spoken about. As explained earlier, Thai is a pro-drop language, and only the skilled student or native speaker is able to figure out from the topic and context who the centers of action and focus are with any degree of certainty. As difficult, or more so, is being able to follow and make sense of conversations involving multiple speakers and the complexities of turn-taking and topic-changing that goes on at a rapid pace. The rapidity of natural speech and the resulting reduction and "smearing" of sounds at boundaries in contrast to the clearly-enunciated, simplified "motherese" of caretaker or teacher talk, is a supreme challenge. Depending on the domain of discourse, the ultimate test of a skilled translator is his or her knowledge of slang and idiomatic usages, in the case of everyday language, or the technical jargon or argot of particular professions -largely a lexical matter, but one which also demands skillful syntactic analytical skills. Syntactic complexities range from equating temporal and spacial relationships in two languages -Thai and English- from such devices as the directionals pay 'to go' and maa 'to come' to reconstructing meaning from widely discontinuous constructions. In interpreting a language, parallel processing goes on between syntax and semantics. Forming an hypothesis about power relationships in a conversation, for example, builds upon the semantic-sytactic cues of utterance-final particles: who is speaking "up or down," (i.e., with or without deference), who is coercing or cajoling whom, and other types of inferences that can be drawn to create a total translation.
    Social appropriateness or "linguistic etiquette" can be sampled on the macro level. Micro-testing would probe the listener's ability to separate out speakers of Standard from non-Standard Thai, and ideally the regional, social, or ethnic background of the speaker, and possibly their values, behaviors and intentions.


Distribution map (19228 bytes)

Map 1.  Rough Geographic Distribution of the Tai Languages

July 2000


Selected References

Bickner, R. J. 1986. "Thai Tones and English Loanwords: A Proposed Explanation." in Papers from a Conference on Thai Studies in honor of William J. Gedney. Bickner, R. J. et al eds. Ann Arbor: Center for South and Southeast Asian Studies. Michigan Papers on South and Southeast Asia, No. 25. pp. 19-41.

Brown, J. M. 1965. From Ancient Thai to Modern Dialects. Bangkok: Social Science Association Press of Thailand, Bangkok.

Cooke, J. R. 1968. Pronominal Reference in Thai, Burmese, and Vietnamese. Berkeley: University of California Press.

Gedney, W. J. 1947. "Indic Loanwords in Spoken Thai." Ph.D. dissertation, Yale University.

Haas, M. R. 1942. "The Use of Numeral Classifiers in Thai," Language, vol. 18, pp. 201-205.

Hartmann, J. F. 1984. The Linguistic and Memory Structure of Tai-Lue Oral Narratives. Monograph Series B-90. Canberra: Australian National University.

Hinds, J. 1988. Conversational Interaction in Central Thai. in The International Symposium on Language and Linguistics. Bamroongraks, Cholticha, et al., eds. pp. 150-163.

Hudak, T. J. 1987. "Thai," in The World's Major Languages, pp. 757-775.

Noss, R. B. 1964. Thai Reference Grammar. Washington, D.C.P Foreign Service Institute.

Smalley, W. A. 1994. Linguistic Diversity and National Unity: Language Ecology in Thailand. Chicago: The University of Chicago Press.

Stein, M. J. 1981. "Quantification in Thai." Ph.D. dissertation. University of Massachusetts.

Tiencharoen, Supanee. 1987. "A Comparative Study of Spoken and Written Thai: Linguistic and Sociolinguistic Perspectives." Ph.D. dissertation. Georgetown University.

Vongvivapanond, Peansiri E. 1992. "Lexicological Significance of Semantic Doublets in Thai." in Papers on Tai Languages, Linguistics, and Literatures in Honor of Willliam J. Gedney on his 77th Birthday. Compton, C. J. and J. F. Hartmann, eds. DeKalb: Center for Southeast Asian Studies. Monograph Series on Southeast Asia, Occasional Paper No.16.

Warotamasikkhadit, Udom. 1972. Thai Syntax. The Hague: Mouton.

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