|Wen-Ma Southern Zhuang|
Dai Zhuang or Thu Lao is a Tai language spoken in Yunnan, China and northern Vietnam. In China is it spoken in Yanshan, Wenshan, Maguan, Malipo, Guangnan counties of Wenshan Prefecture. It is also spoken in Honghe Prefecture. The largest concentrations are in Wenshan (50% of total Zhuang population) and Yanshan (20% of total Zhuang population) counties (Johnson 2011b).
Below are various names (both autonyms and exonyms) for speakers of Dai Zhuang (Johnson 2011a:43).
Johnson (2011b) splits Dai Zhuang into 4 dialects according to tonal splitting patterns: Northern, Central, Southern, and Northeastern. They roughly correspond with the following ethnic subdivisions (Johnson 2011a).
In Vietnam, Thu Lao (autonym: La Hừ, meaning 'black earth') is spoken in the following 7 villages (Nguyễn 2014:14).
Jerold Edmondson describes Thu Lao as a Central Tai language with about 200 speakers that retains voiced initial consonants in low tones, like Tay of Trùng Khánh District, Cao Bằng Province.
Yunnan (1979) reports that a Tai-speaking group called the Baiyi 摆彝 live in Wenshan City, Maguan County, and Qiaotou Township 桥头苗族壮族乡 of Hekou Yao Autonomous County. Yunnan (1979) suggests that it may be similar to Tai Lue. The Baiyi are classified as ethnic Dai in Hekou, and as Zhuang in Wenshan and Maguan. In 1960, the Baiyi had a population of 6,958.
Many Dai Zhuang dialects preserve voiced stops inherited from Proto-Tai (L-Thongkum 1997). L-Thongkum calls the dialects with the voiced stops "Dai Tho," and the dialects without any voiced stops "Tai Tho."