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.
Simeulue
From the ethnic point of view the inhabitants of Simeulue are similar to the people of neighboring Nias Island. Two languages and a number of dialects are spoken on the island: Devayan and Sigulai, which are different from the languages spoken in the north of Sumatra. The majority of the island's population is Muslim.