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.
Lakota language
Lakota (), also referred to as Lakhota, Teton or Teton Sioux, is a Siouan language spoken by the Lakota people of the Sioux tribes. Though generally taught and considered by speakers as a separate language, Lakota is mutually intelligible with the other two languages (such as Dakota language), and is considered by most linguists as one of the three major varieties of the Sioux language.