The Arapahoan languages are a subgroup of the Plains group of Algonquian languages: Nawathinehena, Arapaho, and Gros Ventre. Nawathinehena is extinct and Arapaho and Gros Ventre are both endangered. Besawunena, attested only from a word list collected by Kroeber, differs only slightly from Arapaho, but a few of its sound changes resemble those seen in Gros Ventre. It had speakers among the Northern Arapaho as recently as the late 1920s. Nawathinehena is also attested only from a word list collected by Kroeber, and was the most divergent language of the group. Another reported Arapahoan variety is the extinct Ha'anahawunena, but there is no documentation of it.

Classification

The Glottolog database classifies the Arapahoan languages as follows: