Historical Implications of Click Consonants in Hadza

Click languages are renowned for the novel, popping sounds that speakers use as a part of everyday conversation, a reputation due probably to how rare these sounds are within the world's linguistic inventory. An indication of their scarcity lies in the fact that click languages belong to about thirty groups of people in the world, most of which are found in Botswana, Namibia, South Africa and a few other neighboring countries. In fact, the only non-African click language ever recorded was a now extinct Australian language called Damin, but even then clicks in this language were only used ceremonially during certain rituals. You can hear the pronunciation of some basic click sounds here.

A central theme in the study of click languages, which all have in common this very rare phonetic feature, is their genetic affiliation to each other. In the 1960s, when the influential linguist Joseph Greenberg began studying the African click languages, he grouped all of them under one language family - the Khoisan family - which he named after the two major tribal groups that spoke these various languages; the two groups consisted of herders called the Khoe and hunter gatherers called the San. Since then, however, analysis has shown that Greenberg's definition of the Khoisan family can actually be broken up further into at least three distinct language families, while some of the languages classified as Khoisan don't appear to fit any known language families. One of these isolates is Hadza, a language spoken in Tanzania by about 800 people. Hadza is typologically unusual because of the fact that it's one of just a few languages outside of southern Africa to use clicks (Sandawe and Dahalo being the others). In fact, Hadza is located 2000km away from any other region where click languages are spoken. A combination of its geographical, lexical, and phonetic status has lead many linguists to believe that Hadza is a language isolate, which would mean that it's unrelated to any other known language in the world.