L1 users: 23,500 (2015 census). 8,960 monolinguals. Ethnic population: 23,500 (2015 census).
Attapu province: foot of Bolaven plateau, and near Pakse; Xekong province: Thateng district. Attapu province: Samakkhixai and Sanamxai districts, 7 villages north of Attopeu town; Xekong province: Dakcheung and Lamam districts (Jeng dialect); Attapu, Champasak, and Xekong provinces (Sok dialect).
Riyao, Tamal Euy, Inn Tea, Kranyeu, Khen Sang, Kongsang, La-Nyao, The, Jeng (Cheng, Chiengceng), Sok (Sawk, Sork). Related to Sapuan [spu].