The Kam–Sui languages () are a branch of the Kra–Dai languages spoken by the Kam–Sui peoples. They are spoken mainly in eastern Guizhou, western Hunan, and northern Guangxi in southern China. Small pockets of Kam–Sui speakers are also found in northern Vietnam and Laos. Classification The Kam–Sui branch includes about a dozen languages. Solnit (1988) considers Lakkia and Biao languages to be sister branches of Kam–Sui, rather than part of Kam–Sui itself. The best known Kam–Sui languages are Dong (Kam), with over a million speakers, Mulam, Maonan, and Sui. Other Kam–Sui languages include Ai-Cham, Mak, and Tʻen, and Chadong, which is the most recently discovered Kam–Sui language. Yang (2000) considers Ai-Cham and Mak to be dialects of a single language. Graham Thurgood (1988) presents the following tentative classification for the Kam–Sui branch. Chadong, a language that has been described only recently by Chinese linguist Jinfang Li, is also included below. It is most closely related to Maonan. Cao Miao and Naxi Yao, which are closely related to Southern Dong, have also been added from Shi (2015). Demographics Nearly all speakers of Kam–Sui languages originate in the Qiandongnan (Dong) and Qiannan (Sui, Then, Mak, Ai-Cham) Prefectures of Guizhou, as well as the prefecture-level cities of Hechi (Mulam and Maonan) and Guilin (Chadong) in northern Guangxi. Many Kam–Sui speakers have also migrated to farther urban areas such as Guangzhou. Small groups of Kam and Sui speakers also reside in Tuyên Quang Province, Vietnam, in the villages of Đồng Mộc and Hồng Quang, respectively. By language Mulam 佬 – Luocheng Mulao Autonomous County 罗城仫佬族自治县, Hechi, northern Guangxi; Qiandongnan Prefecture, southeastern Guizhou Dong 侗 – Qiandongnan Prefecture, southeastern Guizhou Then 佯僙/佯爷 – Pingtang County 平塘县, Qiannan Prefecture, southern Guizhou Maonan 毛南 – Huanjiang Maonan Autonomous County 环江毛南族自治县, Hechi, northern Guangxi Chadong 茶洞 – Chadong Township, Lingui County 临桂县, Guilin, northeastern Guangxi Sui 水 – Sandu Shui Autonomous County 黔南布依族苗族自治州, Qiannan Prefecture, southern Guizhou Mak (Mojia) 莫 – Libo County 荔波县, Qiannan Prefecture, southern Guizhou Ai-Cham 锦 – Libo County 荔波县, Qiannan Prefecture, southern Guizhou By location (Listed counterclockwise: east to north to west to south) Guizhou Qiandongnan – Dong; 1,500,000 speakers Qiannan Sandu County – Sui; 300,000 speakers Pingtang County – Then; 15,000 speakers Libo County – Mak and Ai-Cham; 10,000 and 2,700 speakers Guangxi Hechi Luocheng County – Mulam; 86,000 speakers Huanjiang County – Maonan; 30,000 speakers Guilin (Lingui County) – Chadong; 20,000