The work of historical and comparative linguists has long interested African historians. By classifying languages into families, linguists provide models of their historical development that may point to historical events and processes that occurred among peoples speaking those languages. Once classified, linguists can then reconstruct earlier forms of present languages, thus providing direct evidence of words, their meanings and historical influences in the past. Finally, linguists seek to explain innovations that are revealed in their reconstructions by pointing to a combination of internal linguistic developments and different forms of contact that occurred among speakers of different languages.

Simple classification, based largely on counting cognate words in related languages (a technique known as lexicostatistics), is still a very common activity, however, and thus the one most historians rely on, but lexicostatistics gives only a very limited, and often deceptive, view of language history. Historians should thus be aware of its limitations as well as the potential of a number of important techniques now employed by linguists, including the Comparative Method, reconstruction of ancestral languages, and contact models.