Grover Hudson's book is principally a presentation of new lexical evidence for subgrouping within the diverse and numerous group of Semitic languages of Northeast Africa. The history of subclassification of the languages is reviewed, including examination of the literature on the 30 varieties of Northeast African Semitic, which are argued to group as 15 languages. Appropriate use of the term 'Gurage' is examined, and considered limited to recognized members of 'Sebat Bet Gurage'.

The new lexical comparative evidence consists of translation equivalents of a 250-word list, including synonyms, for 14 of the languages, and including cognate proto-language reconstructions of Semitic, Agaw, and East Cushitic. The basic comparisons are presented in tables, and all the 3,301 different words of the tables are presented in a comparative-etymological dictionary, with additional cognates and comparisons. Shared cognates are quantified according to the best grouping of the languages, and as evidence for five groups without the traditional dichotomy into North and South. A new class of evidence is numbers of cognates uniquely shared by the five groups, plus 85 roots thought to be apparent innovations of Proto-Northeast African Semitic. There is no evidence for the long-assumed significant presence of Agaw borrowings in the Northeast African Semitic lexicon.