| 3 million (2016 census)|
Tày (Central Tai)
Tày or Tho (a name shared with Cuoi and with Zuojiang Zhuang of China) is the major Tai language of Vietnam, in the northeast near the Chinese border.
Tày language Wikipedia
Tày consists of,Tày Bảo Lạc is spoken in Bảo Lạc District, western Cao Bang province.
Tày Trùng Khánh is spoken in Trùng Khánh District, northeastern Cao Bang province.
The Dai Zhuang varieties should perhaps be considered the same language.