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.
Copula (linguistics)
In Siouan languages like Lakota, in principle almost all words—according to their structure—are verbs. So not only (transitive, intransitive and so-called 'stative') verbs but even nouns often behave like verbs and do not need to have copulas.