Almost all of these languages are closely related, sharing approximately half of their vocabulary.

These may form a group of their own, which Nurse (2003) calls Peripheral Grassfields but rejects.

Blench (2010) notes there is little evidence for the traditional assumption that the non-Western Momo languages belong in Grassfields and that they may actually be closer to the poorly established Tivoid group; Western Momo is therefore renamed Southwest Grassfields to avoid confusion, and only Menchum and Ambele are left out of Narrow Grassfields.

The classification of Ambele is unclear, though it is clearly divergent, and Menchum may be closer to the Tivoid languages (Blench 2011).

Below is a list of Grassfields language names, populations, and locations (in Nigeria only) from Blench (2019).