The Tai–Kadai languages, also known as Daic, Kadai, Kradai, or Kra–Dai, are a language family of highly tonal languages found in southern China and Southeast Asia. They include Thai and Lao, the national languages of Thailand and Laos respectively. There are nearly 100 million speakers of these languages in the world. Ethnologue lists 92 languages in this family, with 76 of these languages being in the Kam–Tai branch.
The diversity of the Tai–Kadai languages in southeastern China, especially in Guizhou and Hainan, suggests that this is close to their homeland. The Tai branch moved south into Southeast Asia only about a thousand years ago, founding the nations that later became Thailand and Laos in what had been Austroasiatic territory.
The name "Tai–Kadai" comes from an obsolete bifurcation of the family into two branches, Tai and Kadai (all else). Since this Kadai can only be a valid group if it includes Tai, it is sometimes used to refer to the entire family; on the other hand, some references narrow its usage to the Kra branch of the family.
Tai peoples refers to the population of descendants of speakers of a common Proto-Tai language, including sub-populations which no longer speak a Tai language. Some 8-10 million people in Northeastern India (not limited to Assam) claim descent from Ahomese, but may have intermarried with others and now speak Assamese. Additional tens of thousands in India speak Tai languages (mostly in Arunachal Pradesh). Aside from India, where language has eroded, Tai peoples can generally be identified through their language.
Tai, also spelled Dai, peoples of mainland Southeast Asia, including the Thai, or Siamese (in central and southern Thailand), the Lao (in Laos and northern Thailand), the Shan (in northeast Myanmar [Burma]), the Lü (primarily in Yunnan province, China, but also in Myanmar, Laos, northern Thailand, and Vietnam), the Yunnan Tai (the major Tai group in Yunnan), and the tribal Tai (in northern Vietnam). All of these groups speak Tai languages.
Cognates with the name Tai (Thai, Dai, etc.) are used by speakers of many Tai languages. The term Tai is now well-established as the generic name in English. Several Lao linguists have objected to this, opining that Siamese Thai should be considered a Lao language, but that hasn't made much headway in English usage. Because Tai and Thai, the national language of Thailand, are homophones, some linguists continue to use Siamese for the latter. Similarly, the terms Dai and Daic have fallen somewhat out of favor as the name for the entire family, with forms based on Kadai now more common.
Many of the languages are called Zhuang in China and Nung in Vietnam.
An example of Tai scripts