Ghana–Togo Mountain languages

Bernhard Struck, in 1912, was the first to group together these languages under the label Semibantu von Mitteltogo.

[1] This was mainly a loose geographical-typological grouping based on the elaborate noun class systems of the languages; lack of comparative data prevented a more definitive phylogenetic classification.

Bernd Heine (1968) carried out comparative research among the group, establishing a basic division between Ka-Togo and Na-Togo based on the word for 'flesh' in the languages.

Heine (1968) placed the GTM languages into two branches of Kwa, Na-Togo and Ka-Togo: However, this classification was distorted by influence from Ewe on the one hand and Twi on the other.

As with Heine's classification, these may be independent branches of Kwa: Ethnologue also lists Agotime, which they note is similar to Ahlo.