Niger-Congo is a hypothetical language family spoken over nearly the entirety of sub-Saharan Africa. It unites the Mande languages (a family with a similar level of diversity as the Indo-European languages), the Atlantic-Congo languages (which share a characteristic noun-class system), and possibly several smaller groups of languages that are difficult to classify. If valid, Niger-Congo would be the world's largest in terms of member languages, the third-largest in terms of speakers, and Africa's largest in terms of geographical area. It is generally considered to be the world's largest language family in terms of the number of distinct languages, just ahead of Austronesian, although this is complicated by the ambiguity about what constitutes a distinct language; the number of named Niger-