The Khoisan languages compose the smallest phylum of African languages.
The Bantu languages adopted the use of clicks from neighboring Khoisan populations, often through intermarriage, while the Dahalo are thought to have retained clicks from an earlier Khoisan-like language when they shifted to speaking a Cushitic language.
Language Universals and Linguistic Typology: Syntax and Morphology
It is fair to say that of all the language families of the world, the Khoisan languages are among the most neglected by language scholars and the least studied.
The language is used at all levels of education and in the media.
Many of the Khoisan languages have five vowels /i/, /e/, /a/, /o/, /u/ which can be produced with additional features, such as nasalization, pharyngealization, and different voice qualities such as breathy and creaky voice, sometimes resulting in up to 40 different vowels.