Khoe–Kwadi languages in the context of "Khoikhoi"

The number of languages natively spoken in Africa is variously estimated (depending on the delineation of language vs. dialect) at between 1,250 and 2,100, and by some counts at over 3,000. Nigeria alone has over 500 languages (according to SIL Ethnologue), one of the greatest concentrations of linguistic diversity in the world. The languages of Africa belong to many distinct language families, among which the largest are:

• Niger–Congo, which include the large Atlantic-Congo and Bantu branches in West, Central, Southeast and Southern Africa.
• Afroasiatic languages are spread throughout Western Asia, North Africa, the Horn of Africa and parts of the Sahel.
• Saharan, Nilotic and Central Sudanic languages (grouped under the hypothetical Nilo-Saharan macro-family), are present in East Africa and Sahel.
• Austronesian languages are spoken in Madagascar and parts of the Comoros.
• Khoe–Kwadi languages are spoken mostly in Namibia and Botswana.
• Indo-European languages, while not indigenous to Africa, are spoken in South Africa and Namibia (Afrikaans, English, German) and are used as lingua francas in Liberia and the former colonies of the United Kingdom (English), former colonies of France and of Belgium (French), former colonies of Portugal (Portuguese), former colonies of Italy (Italian), former colonies of Spain (Spanish) and the current Spanish territories of Ceuta, Melilla and the Canary Islands and the current French territories of Mayotte and La Réunion.

There are several other small families and language isolates, as well as creoles and languages that have yet to be classified. In addition, Africa has a wide variety of sign languages, many of which are language isolates.

Khoisan (/ˈkɔɪsɑːn/ KOY-sahn) or Khoe-Sān (pronounced [kʰoɪˈsaːn]) is an umbrella term for the various indigenous peoples of Southern Africa who traditionally speak non-Bantu languages, combining the Khoekhoen and the Sān peoples. Khoisan populations traditionally speak click languages. They are considered to be the historical communities throughout Southern Africa, remaining predominant until Bantu and European colonisation. The Khoisan have lived in areas climatically unfavourable to Bantu (sorghum-based) agriculture, from the Cape region to Namibia and Botswana, where Khoekhoe populations of Nama and Damara people are prevalent groups. Considerable mingling with Bantu-speaking groups is evidenced by prevalence of click phonemes in many Southern African Bantu languages, especially Xhosa.

Many Khoesan peoples are the descendants of an early dispersal of anatomically modern humans to Southern Africa before 150,000 years ago. (However, see below for recent work supporting a multi-regional hypothesis that suggests the Khoisan may be a source population for anatomically modern humans.) Their languages show a limited typological similarity, largely confined to the prevalence of click consonants. They are not verifiably derived from a single common proto-language, but are split among at least three separate and unrelated language families (Khoe-Kwadi, Tuu and Kxʼa). It has been suggested that the Khoekhoe may represent Late Stone Age arrivals to Southern Africa, possibly displaced by Bantu expansion reaching the area roughly between 1,500 and 2,000 years ago.

Khoikhoi (/ˈkɔɪkɔɪ/ KOY-koy) (or Khoekhoe in Namibian orthography) are the traditionally nomadic pastoralist indigenous population of South Africa. They are often grouped with the hunter-gatherer San (literally "foragers") peoples, the accepted term for the two people being Khoisan. The designation "Khoikhoi" is actually a kare or praise address, not an ethnic endonym, but it has been used in the literature as an ethnic term for Khoe-speaking peoples of Southern Africa, particularly pastoralist groups, such as the Inqua, Griqua, Gonaqua, Nama, Attequa. The Khoekhoe were once known as Hottentots, a term now considered offensive.

The Khoekhoe are thought to have diverged from other humans 100,000 to 200,000 years ago. In the 17th century, the Khoekhoe maintained large herds of Nguni cattle in the Cape region. They mostly gave up nomadic pastoralism in the 19th to 20th century.

Kwadi /ˈkwɑːdi/ is an extinct "click language" once spoken in the southwest corner of Angola. It became extinct around 1960. There were only fifty Kwadi in the 1950s, of whom only 4–5 were competent speakers of the language. Three partial speakers were known in 1965, but in 1981 no speakers could be found. Salvage work was carried out in 2014 with two rememberers who had acquired the language from an old speaker while they were children.

Although Kwadi is poorly attested, there is enough data to show that it is a divergent member of the Khoe family, or perhaps cognate with the Khoe languages in a Khoe–Kwadi family. It preserved elements of proto-Khoe that were lost in the western Khoe languages under the influence of Kxʼa languages in Botswana, and other elements that were lost in the eastern Khoe languages.