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.
Siwai language
Motuna or Siwai, also known as "Telei, Rugara", is a Papuan language of Bougainville Province, Papua New Guinea. The current number of speakers is difficult to estimate since the latest figure (6,000 + 600) is from the 1970 census.