This comprehensive study of the vocabulary and grammar of the Yemsa language, also compares Yemsa with other Cushitic and Omotic languages, with west African languages and with European languages. Interesting are the discussion of the systematic Yemsa tonal distinctions, which are considered to function as gender distinction and distinction of nouns from verbs; the discussion of the Yemsa use of five cases to express locations; and the investigation of the expression of emphasis.