In 1963, Greenberg has provided us with a genetic classification of the languages of Africa that by and large has been adopted by the field and has earned him worldwide recognition. His work stimulated generations of linguists to do more work on the nature of genetic relationship in Africa.
But in addition to genetic relationship there is a second kind of historical language relationship, commonly referred to as areal (or contact-induced) relationship. Our knowledge of this kind of relationship in Africa is scanty, to say the least; I know of no substantial work on this issue. Still, it is widely held that for a better understanding of the linguistic and cultural history of Africa, areal classification work is hardly less important than genetic classification.
In 1959, Greenberg published a paper which had the same title as the present paper. In that paper he discussed some properties that define Africa as a linguistic macro-region. In addition he suggested that also within Africa there are some noteworthy areal groupings. This paper can be viewed as proposing a research program on areal linguistics in Africa. Unfortunately, neither Greenberg nor anyone else has taken this program up.
In my paper I will try to show that roughly forty years after
Greenberg's paper was published there is now something like a research program
evolving, and I will present some findings that are emerging within this program.