Tai Dam language

Tai Dam (), also known as Black Tai (Thai: ; ; "Black Tai language"; ), is a Tai language spoken by the Tai Dam in Vietnam, Laos, Thailand, and China (mostly in Jinping Miao, Yao, and Dai Autonomous County).
The Tai Dam language is similar to Thai and Lao, but it is not close enough to be readily understood by most Thai and Lao speakers. In particular, the Pali and Sanskrit additions to Thai and Lao are largely missing from Tai Dam.
Geographical distribution.
Tai Dam is spoken in Vietnam, China, Laos, and Thailand. In central Thailand, it is known as Thai Song.
Tai Dam speakers in China are classified as part of the Dai nationality along with almost all the other Tai peoples. But in Vietnam they are given their own nationality (with the White Tai) where they are classified (confusingly for English speakers) as the Thái nationality (meaning Tai people).
In China, Tai Dam () people are located in the following townships of Yunnan, with about 20,000 people in Yunnan (Gao 1999).
Official status.
In Vietnam, all Tai peoples are taught a standardized Tai language based on the Tai Dam language, using the standardized Tai Viet script.
Vocabulary.
The Pali and Sanskrit additions to Thai and Lao are generally absent from Tai Dam. Tai Dam lacks many of the Khmer and Indic (via Khmer) loan words found in Thai, Lao and Isan.
Writing system.
The Tai Dam language has its own system of writing, called Tai Viet, which consists of 31 consonants and 14 vowels. Although the language is tonal, there are no tone markers, as there are in Thai and Lao. According to Thai authors, the writing system is probably derived from the old Thai writing of the kingdom of Sukhotai.