Kasem is a Central Gur language belonging to the Northern Grusi group, the only representative of this group to be found in Ghana. The language homeland is in the Kassena-Nankani district of the Upper East Region, in the recently established Paga district, and across the northern Ghana border in Burkina Faso. The main towns are Navrongo, Paga and Chiana in Ghana; Pô, Tiébélé, and Guiaro in Burkina Faso.
With the exception of Firi, spoken west of the Sisili river, there is general inter-comprehension across the language area in spite of some dialect variations. This dictionary notes some of the variants, e.g. between Navrongo, Chiana and Paga. Generally these variations can be seen as a source of enrichment rather than confusion.