Thailand is home to 51 living indigenous languages and 24 living non-indigenous languages, with the majority of people speaking languages of the Southwestern Tai family, and the national language being Central Thai. Lao is spoken along the border with the Lao PDR; Karen languages are spoken along the border with Myanmar; Khmer is spoken near Cambodia; and Malay is spoken in the south near Malaysia. Sixty-two 'domestic' languages are officially recognized, and international languages spoken in Thailand, primarily by international workers, expatriates and businesspeople, include Burmese, Karen, English, Chinese, Japanese, and Vietnamese, among others.

Officially recognized languages

National breakdown The following table comprises all 62 ethnolinguistic groups recognized by the Royal Thai Government in the 2011 Country Report to the UN Committee responsible for the International Convention on the Elimination of All Forms of Racial Discrimination, available from the Department of Rights and Liberties Promotion of the Thai Ministry of Justice.

+Five language families of Thailand recognized by the Royal Thai GovernmentKra–DaiAustroasiaticSino-TibetanAustronesianHmong-Mien24 Groups22 Groups11 Groups3 Groups2 GroupsKaloengKasongGuong (Ugong)Malay (Malayu / Nayu / Yawi)Hmong (Meo)Northern ThaiKuy / KuayKaren (7 subfamilies) Moken / MoklenMien (Yao)Tai DamKhmu- S'gaw KarenUrak Lawoi'NyawThailand Khmer, Northern Khmer- Pwo Karen KhünChong- Kaya KarenCentral ThaiSa'och- Bwe Karen Thai KoratKensiu- Pa'O Thai TakbaiSamre- Padaung Karen Thai LoeiThavung- Kayo KarenTai LueSoJingpaw / Kachin Tai YaNyah Kur (Chaobon)Chinese ShanNyeuYunnanese Chinese Southern ThaiBru (Kha)Bisu Phu ThaiBlang (Samtao)Burmese PhuanPalaung (Dala-ang)Lahu (Muzur) YongMonLisu YoyLawaAkha Lao KhrangMlabri (Tongluang)Mpi Lao NgaewLamet (Lua) Lao TiLavua (Lawa / Lua) Lao Wiang/Lao KlangWa Lao LomVietnamese Isan Saek

Regional breakdown Regional language data is limited. The following table shows all the language families of Northeast Thailand, as recognized in the report which is the source for the national breakdown.

+ Language families of Northeast ThailandTai Language FamilyPersonsAustroasiatic Language FamilyPersonsLao Esan / Thai Lao13,000,000Thailand Khmer / Northern Khmer1,400,000Central Thai800,000Kuy / Kuay (Suay)400,000Thai Khorat / Tai Beung / Tai Deung600,000So70,000Thai-Loei500,000BrucombinedPhu Thai500,000Vietnamese20,000Ngaw500,000Nyeu10,000Kaleung200,000 forNyah Kur / Chao Bon / Khon Dong7,000Yoy Kaleung, Yoy and Phuan So (Thavaung)1,500PhuancombinedMon1,000Tai-dam (Song)(not specified)Total:16,103,000Total:1,909,000Cannot specify ethnicity and amount:3,288,00021,300,000 Note that numbers of speakers are for the Northeast region only. Languages may have additional speakers outside the Northeast.

Provincial breakdown Provincial-level language data is limited; those interested are directed to the Ethnolinguistic Maps of Thailand resource, or to the Ethnologue Thailand country report. +Khmer speakers as a percentage of the total population in various provinces of ThailandProvinceKhmer % in 1990Khmer % in 2000BuriramChanthaburiMaha SarakhamRoi EtSa KaewSisaketSurinTratUbon Ratchathani

Topolects

The sole official language of Thailand is Central Thai (Siamese), a vernacular language in Central (including the Bangkok Metropolitan Region), Southwestern, and Eastern Thailand, along with Thai Chinese ethnic enclaves in outer parts of the country such as Hatyai, Bandon, Betong, Nangrong, Mueang Buriram, Mueang Khonkaen, Mueang Udonthani, and recently luxury housing estates in Hangdong. Central Thai is a Kra–Dai language closely related to Lao, Shan, and numerous indigenous languages of Southern China and Northern Vietnam. It is the sole language of government and education (however, international schools use English, and Yunnanese schools in Maesai use Mandarin). Technically, although almost all Thai nationals are Central Thai native speakers, the Krungthep dialect is usually used as a courtesy when speaking to strangers, even if all parties share a same (non-Central Thai) primary language; however, less than half of the population claim to use Central Thai as their vernacular language. Standard Thai is written in the Thai alphabet, an abugida that evolved from the Khmer script.

Thai has several topolects (variations). Central Thai and Southern Thai are successors of the Sukhothai language, which divided during the 17th century, and are mutually intelligible (like English and Scots). Northern Thai is spoken in the northern provinces that were formerly part of the independent kingdom of Lan Na, while Isan (a Thai variant of Lao) and Phu Thai are native languages of the northeast. These languages are partially mutually intelligible with Central Thai, with the degree depending on standard sociolinguistic factors. Although most linguists classify all these as separate languages, the Thai government has historically treated them as dialects of Thai to build Thai national identity. In the 2010 national census, no declared language option was given besides Thai.

Since the Thai government and Royal Society treat the topolects as dialects, the varieties of Central Thai itself are downplay and disregarded; however, local Central Thai accent discrimination still occurs and is called a ner (). Central Thai has six varieties, as follows:

Krungthep accent – Traditionally, this accent has been associated with the Teochews settlers (Krungthepians, Padreewian, Chonburian, Photaramian-Banpongs, Hatyais, Mueang Khonkaens etcs.), who experienced language purge in the early 20th century to Central Thai through the Thai education system. Due to insufficient contact with the Rattanakosin speakers, this led to the uniqueness of both its pronunciation and its colloquial form. However, at present the situation has reversed (Thaification) and the dialect now carries the highest social prestige and cultural imperialism as of the late 20th century.Same stereotype to the Received Pronunciation in United Kingdom, the accent was formed by sociolinguistics rather than dialect continuum, is the sole accent found scattered and hegemony throughout the country, the claim that the Krungthep accent is non-regional is still disputed, since the term Krungthep refers absolutely to Bangkok CBD, the homeland of Teochews, however, sub-varieties in Bandon and Hatyai districts, which incorporate many Southern Thai features, the dialect are known as Laeng Kha Luang (, literally: Official Pronunciation).An estimated 10% of Thais speak with this accent. Notable speakers with a proper Krungthep accent who are not Thai Chinese speakers include Theerathon Bunmathan, Teerasil Dangda, Siwarak Tedsungnoen, Kiatisuk Senamuang (however, they all grew up in Thai Chinese communities). Due to the low number of internal migrats, Mueang Chon is known as the district with the highest percentage of its population speaking the Krungthep accent. Rattanakosin accent – An authentic accent of the Bangkok periphery that was used in mainstream media, however, the situation has reversed in late 20th century when this accent was downgraded to lower prestige, and is now referred to as 'fresh market' or 'janitor' accent, and the prestige accent was replaced by Krungthep accent. The term Rattanakosin here refers to the Rattanakosin era, during which this accent was prevalent, not to the Rattanakosin Island. The Royal Society registers phonology on this accent.The Rattanakosin accent was once part of the Ayutthaya dialect, as evident in the standard Thai media during the era of Field Marshal Plaek Phibunsongkhram's government (mid-20th century). As Bangkok expanded rapidly after the 1980s, Krungthepians migrated to the surrounding areas, which influence the locals into their dialect. Today, the Krungthep and Rattanakosin accents are concerned only with matters of pronunciation; in other aspects of Central Thai, such as vocabulary, grammar, and style, both follow the Krungthepian features. Despite these two matters of pronunciation have big differences, the Royal Society looking further downplay as the same dialect called Krungthep dialect, mainly for nation harmony).Recently, the only Thai Prime Minister to speak with a Rattanakosin accent is Surayud Chulanont. With the other exception of Yingluck Shinawatra, who speaks with a Chiang Mai accent (Northern Thai language), all other Prime Ministers are Thai Chinese and have spoken with a Krungthep accent. Ayutthaya era dialect (remnant) – This dialect is spoken in most part of lower Central Thailand, Kanchanaburi, Rayong, Chanthaburi, and Trat provinces. The city of Ayutthaya was rebuilt during the reign of King Mongkut, and today the Rattanakosin accent is primarily used. The Suphanburi accent has most preserved its identity from the Ayutthaya era. Northern Cities dialect – A dialect continuum with the Northern Thai language, spoken in upper Central Thailand (Northern Cities) and part of Uttaradit province. Southwestern dialect – A dialect continuum with the Southern Thai language, spoken from Mueang Prachuap district to most parts of Ratchaburi province. Khorat dialect – A mixed form of speech in which Central Thai and Laotian elements and structures are combined arbitrarily.

The Krungthep, Rattanakosin, and Suphanburi accents can be compared to the English accents of Received Pronunciation, Cockney and Scouse.

Minority languages The position of all minority languages, including the largest (e.g. Isan in the Northeast and Kham Muang in the North), is precarious given that they are not well-supported in Thailand's language education policy. In the far south, Kelantan-Pattani Malay, also known as Yawi, is the primary community language of the Malay Muslims. Khmer is spoken by older Northern Khmer. Varieties of Chinese are also spoken by the older Thai Chinese population, with the Teochew dialect being best represented. However, the younger Thai Chinese and Northern Khmer trend toward speaking Central Thai. The Peranakan in Southern Thailand speak Southern Thai at home.

Sign languages

Several village sign languages are reported among the mountain peoples ('hill tribes'), though it is not clear whether these are independent languages, as only Ban Khor Sign Language has been described. Two related deaf-community sign languages developed in Chiangmai and Bangkok; the national Thai Sign Language developed from these under the influence of American Sign Language.

Endangerment status of languages The 2014 Ethnologue country report for Thailand, which uses the EGIDS language endangerment assessment scale, lists one national language (Central Thai), one educational language (Isan), 27 developing languages, 18 vigorous languages, 17 threatened languages, and 7 dying languages.

Most widely spoken languages

ICERD 2011 country report data The following table shows ethnolinguistic groups in Thailand with equal to or more than 400,000 speakers according to the Royal Thai Government's 2011 Country Report to the Committee Responsible for the International Convention on the Elimination of All Forms of Racial Discrimination (ICERD).:99 and the Ethnolinguistic Maps of Thailand project. Note that the degree to which language speakers will have shifted in their idiolects towards Central Thai will depend on standard sociolinguistic factors, like age, education, gender, and proximity to an urban center.

Ethnolinguistic groups of Thailand with equal to or more than 400,000 speakers:99 Language Speakers Language Family Central Thai million Tai-Kadai Isan million Tai-Kadai Kham Muang (Northern Thai) million Tai-Kadai Pak Tai (Southern Thai) million Tai-Kadai Northern Khmer million Austroasiatic Yawi (Pattani Malay) million Austronesian Ngaw million Tai-Kadai Phu Thai million Tai-Kadai Karen million Sino-Tibetan Kuy million Austroasiatic

Ethnologue data