Siouan languages
Siouan languages can be grouped into the Western Siouan languages and Catawban languages. The Western Siouan languages can be divided into Missouri River languages (such as Crow and Hidatsa), Mandan, Mississippi River languages (such as Dakotan, Chiwere-Winnebago, and Dhegihan languages), and Ohio Valley Siouan branches. The Catawban languages consist only of Catawban and Woccon.
Sioux
These later studies identify Assiniboine and Stoney as two separate languages, with Sioux being the third language. Sioux has three similar dialects: Lakota, Western Dakota (Yankton-Yanktonai) and Eastern Dakota (Santee-Sisseton). Assiniboine and Stoney speakers refer to themselves as "Nakhóta" or "Nakhóda" (cf. Nakota).