Distribution of the Tai–Kadai language family
- Saek (Laos and northeast Thailand; listed outside Tai proper in the Ethnologue classification, though said to be similar to Tai Maen, which is listed as Northern Tai)
- Tai Maen (Laos)
- Yoy (Thailand) [?]
- Bouyei (Buyi) (China) (including the language of the Giáy people of Vietnam)
- Central Hongshuihe Zhuang
- Eastern Hongshuihe Zhuang
- Guibei Zhuang
- Yei Zhuang
- Lianshan Zhuang
- Liujiang Zhuang
- Liuqian Zhuang
- Yongbei Zhuang
- Youjiang Zhuang
(See varieties of Zhuang.)
Longsang Zhuang, a recently described Northern Tai language, is spoken Longsang Township, Debao County, Guangxi, China. Hezhang Buyi is a moribund Northern Tai language of northwestern Guizhou that is notable for having a Kra substratum.
Pittayaporn (2009:300) distinguishes a similar group of Zhuang varieties as group "N", defined by the phonological shifts *ɯj, *ɯw → *aj, *aw. He moves the prestige dialect of Zhuang, the Wuming dialect, from the Northern Tai Yongbei Zhuang to Yongnan Zhuang - purportedly Central Tai - as it lacks these shifts. The various languages and localities Pittayaporn includes in group N, along with their Ethnologue equivalents, are:
- Bouyei 布依 (including the language of the Giáy people of Vietnam)
- Yei Zhuang 剥隘
- (Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan)
- (Baise, Guangxi)
- (Nanning Prefecture, Guangxi)
- (Guigang Prefecture, Guangxi)
- Laibin 来宾 Prefecture, Guangxi = Hongshuihe Zhuang (south Laibin), Liujiang Zhuang (north Laibin)
- (Hechi Prefecture, Guangxi)
- (Liuzhou Prefecture, Guangxi)
- Longsheng 龙胜县, Guilin 桂林, Guangxi = Guibei Zhuang
- Dong'an 东安县, Yongzhou 永州, Hunan
- Lianshan 连山县, Qingyuan 清远, Guangdong = Lianshan Zhuang
- Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, eds. (2017). "Northern Daic". Glottolog 3.0. Jena, Germany: Max Planck Institute for the Science of Human History.
- Pittayaporn classified Yoy as Southwestern Tai, but does not provide supporting analysis.
- Pittayaporn, Pittayawat. 2009. The Phonology of Proto-Tai. Ph.D. dissertation. Department of Linguistics, Cornell University.