The Thổethnic group inhabits the mountainous regions of northern Vietnam, mainly Nghệ An Province southwest of Hanoi. Many Thổ speak the Tho language, which is closely related to Vietnamese. The Thổ population numbered 91,430 in 2019. The Thổ are one of the 4 main groups of Vietic speakers in Vietnam, the others being the Kinh, Muong, and Chứt. The name Thổ, which means "autochthonous" was originally applied to the Tày ethnic group, however this usage is obsolete.
History
The Thổ people are a heterogeneous mix of different Vietic peoples. Around the end of the 17th century, Vietnam experienced multiple social upheavals that caused multiple migrations of Viet and Muong peoples into territory of other Vietic speaking ethnic minorities such as the Cuối and intermixed with the local populations. After a period of evolution, were given the name Thổ. Their culture combines elements of Viet and Muong culture, with elements of Thái culture. Their clothing is a mix of Vietnamese, Muong, and Tai traditions from the early modern period. Some women wear clothing similar to the Áo bà ba or the Áo tứ thân, but with a Sarong and a Kerchief. Men wear simple tunics and pants. Just like with the Muong, many clothing items are purchased from the Thái. They mainly grow rice and ramie, and use hemp to make bags, hammocks and nets. In the northern communes of Nghệ An, the stilt houses are identical to that of the Muong. In the South, however, they are in the Thái style.
Subdivisions
Thổ consists of various different ethnolinguistic groups. Quán Vi Miên lists the following branches.
Thổ is a heterogeneous group; thus, local groups have distinct languages. However, all of Thổ languages belong to Vietic branch. Nguyễn Hữu Hoành classify Thổ languages into 5 groups base on their position in Vietic branch.
Tày Poọng and Đan Lai - Lexicostatistical studies have found that Đan Lai and Poọng sharing 85% basic lexicon. Thus, Nguyễn identify them as dialects of a language. The speakers of this language reside mainly in Con Cuông and Tương Dương districts. It may also have close relation with Hung language in Laos.
Cuối, Nguyễn pointed out that Cuối is a distinct language with Vietnamese, Muong and Poọng-Đan Lai. This language have two dialects Cuối Chăm in Tân Hợp commune and Cuối Nếp in Thái Hòa town. Because of sharing 66% basic lexicon with Poọng, Nguyễn proposed to group Cuối with Tày Poọng-Đan Lai to form a subbranch in Vietic, parallel to Việt-Mường branch and Chứt branch.
Mọn and Họ, The two dialects share 98% basic lexicon and have a closer relation with Mường languages than Cuối and Poọng. They share 77%, 79% and 71% core lexicon with Mường Bi language, Mường Ống language and Nghệ An dialect of Vietnamese, respectively. Especially, Mọn and Họ are lexical closest with a Mường language in Như Xuân district. Therefore, Nguyễn group them into a single language in Việt-Mường branch which have a closer relation with Mường languages. Maspéro named this language as Southern Mường language
Kẹo share 99% lexicon with Nghệ An dialect of Vietnamese. Thus, Nguyễn classified Kẹo as a dialect of Vietnamese or even a sub-dialect of Nghệ An dialect
Thổ Lâm La and Thổ Như Xuân''' share respectively 94% and 95% basic lexicon with Nghệ An dialect. However, Nguyễn argued that two Thổ languages experienced a different phonological innovation with Vietnamese. Thus, he place it into a grey area between being dialects of Vietnamese or being member languages of Viet-Muong branch.
Distribution
As of 2009, 80% of all ethnic Thổ live in Nghệ An Province, while 13% are found in Thanh Hóa Province Quán Vi Miên. Quán Vi Miên lists ethnic Thổ populations and branches for the following districts of Nghệ An Province.
Quỳ Hợp District: 18,394 people; Họ, Kẹo, Mọn branches, in the following communes:
*Tam Hợp
*Nghĩa Xuân
*Minh Hợp
*Hạ Sơn
*Văn Lợi
*Thọ Hợp
*Quỳ Hợp city
Nghĩa Đàn District: 28,487 people; Họ, Kẹo, Mọn, Cuối Đếp branches
Tân Kỳ District: 15,695 people; Họ, Kẹo, Mọn, Cuối Chăm branches
Con Cuông District: 3,220 people; Đan Lai, Ly Hà branches