Book excerpt: This advanced historical linguistics course book deals with the historical and comparative study of African languages. The first part functions as an elementary introduction to the comparative method, involving the establishment of lexical and grammatical cognates, the reconstruction of their historical development, techniques for the subclassification of related languages, and the use of language-internal evidence, more specifically the application of internal reconstruction. Part II addresses language contact phenomena and the status of language in a wider, cultural-historical and ecological context. Part III deals with the relationship between comparative linguistics and other disciplines. In this rich course book, the author presents valuable views on a number of issues in the comparative study of African languages, more specifically concerning genetic diversity on the African continent, the status of pidginised and creolised languages, language mixing, and grammaticalisation.