Image: Mai Siam

The Language

Thai (ภาษาไทย, transcription: phasa thai, transliteration: p̣hā sā thịy;, 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.

Languages and dialects

Standard Thai, also known as Central Thai or Siamese, is the official language of Thailand, spoken by about 65 million people (1990) including speakers of Bangkok Thai (although the latter is sometimes considered as a separate dialect). Khorat Thai is spoken by people in the Northeast of Thailand started from Nakhon Ratchasima onward; it occupies a linguistic position somewhere between Central Thai and Isan on a dialect continuum, and may be considered a variant or dialect of either.

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:

  • Street Thai (ภาษาพูด, spoken Thai): informal, without polite terms of address, as used between close relatives and friends.
  • Elegant Thai (ภาษาเขียน, 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): (influenced by Khmer) used when addressing members of the royal family or describing their activities.

Many Thais can speak at only the first and second levels, though they will understand the others.



Main article: Thai alphabet

The Thai alphabet is derived from the Khmer alphabet (อักขระเขมร), which is modeled after the Brahmic script from the Indic family. However, the language itself and its alphabet is considered by some to be also heavily related and derived from the Lao alphabet. Most Laotians are able to read Thai writing as well as speak it as more than half of the Thai language, its grammar, intonation, vowels and so forth are all 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:

1.  It is an abugida script, in which the implicit vowel is a short /a/ for consonants standing alone and a short /o/ if the initial consonant or cluster is followed by another consonant.

2. Tone markers are placed above the initial consonant of a syllable or on the last consonant of an initial consonant cluster.

3. Vowels associated with consonants are nonsequential: they can be located before, after, above or below their associated consonant, or in a combination of these positions.
The latter in particular causes problems for computer encoding and text rendering.


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, 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.