Classification
The languages of Africa display an astonishing variety of complex tone systems, and a correspondingly large body of literature has grown up in an attempt to understand them. Together with East Asia, Africa has probably the highest ratio of tonal to non-tonal languages, with tonal languages found in just about every language family with the exception of Semitic and Berber. In particular, the Niger-Congo family, which subsumes most of the sub-Saharan languages, including the Bantu group, is almost entirely tonal (or occasionally accentual). Table 6.1, based largely on Bendor-Samuel 1989, shows the affiliation of the major tonal languages of Africa, including all those discussed in this chapter.
Common or striking characteristics of African tone languages
By most estimates Africa contains well over a thousand languages, with the Niger-Congo group alone having more than 900; among the Bantu languages, at least fifteen are spoken by more than three million people, and at least six are spoken by more than five million. As one might expect in such a huge group of languages covering such an enormous geographical area, there is great diversity in their tonal systems. Nonetheless, one can identify some characteristics that are particularly widespread in Africa, and much less common in Asia or Central America, which we shall look at in later chapters.
The theoretical literature on tone has been dominated by studies of African languages, and as a result an understanding of African systems is a foundation for a study of other areas from a theoretical perspective.