Arapaho is a member of the Algonquian family of languages. Languages in this family are or were widely spoken on the eastern seabord, northeast and upper midwest of the US, and in eastern Canada. Among the Algonquian languages are Cree, Ojibway, Micmac, Massachusetts, Delaware, Shawnee, Menominee, Potawatomi and Powhatan (the language of Pocohantas).

Arapaho is one of a group of Algonquian languages spoken on the Great Plains, in an area separate from the main speech area. Related to Arapaho are Cheyenne, Blackfoot and Gros Ventre. The Arapaho language has changed rapidly over the centuries, and does not closely resemble other Algonquian languages in many ways. Arapaho language evolution is very interesting.

The Algonquian languages and peoples have played an important part in American history. All the tribes initially encountered by English settlers were Algonquian, and these farming peoples shared their crops such as corn, squash, beans and pumpkins with the new arrivals. The first book printed in the US was a translation of the Bible, printed in the Massachusett language, in the early 1600's. The majority of words borrowed into English from Native American languages are Algonquian in origin, including moccasin, moose, wigwam, wampum, toboggan, and place names including Massachusetts and Connecticut.

Today, many of the Algonquian language are either extinct or threatened with extinction. No children are currently learning Arapaho as a first language spoken in the home. Virtually all of the fluent, native speakers of Arapaho (who learned Arapaho as their first language) are now over the age of 50. Certainly less than 500 people still speak Arapaho, concentrated overwhelmingly among the Northern Arapaho in Wyoming.