Linguistic evidence indicates that both Cushitic speakers and Omotic speakers are present in Ethiopia by about 7000 BCE at the latest.

Linguistic diversification within each group thereafter gives rise to a large number of new languages.

In the case of Cushitic, these include Agew in the central and northern highlands and, in regions to the east and southeast, Saho, Afar, Somali, Sidamo, and Oromo, all spoken by peoples who will play major roles in the subsequent history of the region.

Omotic also spawns a large number of languages, Welamo (often called Wolayta) and Gemu-Gofa being among the most widely spoken of them, but Omotic speakers will remain outside the main zone of ethnic interaction in Ethiopia until the late nineteenth century.