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.
Quapaw language
The Quapaw language does not conform well to English language phonetics, and a writing system for the language has not been formally adopted. All of the existing source material on the language utilizes different writing systems, making reading and understanding the language difficult for the novice learner. To address this issue, an online dictionary of the Quapaw language is being compiled which incorporates all of the existing source material known to exist into one document using a version of the International Phonetic Alphabet which has been adapted for Siouan languages.