Crabb (1969)[1] remains the major monograph on these languages, although regrettably, Part II, which was to contain grammatical analyses, was never published.

The nearby Mbe language is the closest relative of Ekoid[2] and forms with it the Ekoid–Mbe branch of Southern Bantoid.

[3] Proto-Ekoid is reconstructed with the following vowels and tones: */i e ɛ a ɔ o u/; high, low, rising, falling, and downstep.

[9] Although Koelle lumped his specimens in the same area, it seems that Cust (1883)[10] was the first to link them together and place them in a group co-ordinate with Bantu but not within it.

Ekoid has raised particular interest among Bantuists because it has a noun-class system that seems close to Bantu and yet it cannot be said to correspond exactly (Watters 1980).