The Rift languages are named after the
Great Rift Valley of Tanzania, where they are found.
Hetzron (1980:70ff) suggested that the Rift languages (South Cushitic) are a part of
Lowland East Cushitic. Kießling & Mous (2003) have proposed more specifically that they be linked to a Southern Lowland branch, together with
Oromo,
Somali, and
Yaaku–Dullay. It is possible that the great lexical divergence of Rift from East Cushitic is due to Rift being partially influenced through contact with
Khoisan languages, as perhaps evidenced by the unusually high frequency of the ejective affricates and , which outnumber pulmonary consonants like . Kießling & Mous suggest that these ejectives may be remnants of
clicks from the source language. Some few loanwords from sources akin to
Sandawe and
Hadza are known that demonstrate this form of
click loss: •
Dental click → sibilant affricate: Sandawe 'snake'; — Alagwa , Burunge 'python', Kwʼadza •
Lateral click → lateral affricate: Sandawe 'bow', Hadza 'poisoned arrow'; — Iraqw 'quiver of arrows', Kwʼadza 'arrows (plural)' Ehret proposes also a further source for the copious of West Rift: unconditional ejectivization of all other proto-Rift affricates such as , , , which would have remained partly distinct in Kwʼadza and Aasax, e.g. Proto-Rift 'chick' > Iraqw , Kwʼadza . The terms "South Cushitic" and "Rift" are not quite synonymous: The
Ma'a and
Dahalo languages were once included in South Cushitic, but were not considered Rift. Kießling restricts South Cushitic to West Rift as its only indisputable branch. He states that Dahalo has too many East Cushitic features to belong to South Cushitic, as does Ma'a. (The
Waata and
Degere may once have spoken languages similar to Dahalo.) He deems Kw'adza and Aasax in turn insufficiently described to classify as even Cushitic with any certainty. Kruijsdijk (2024) argues for continuing to maintain Kw'adza and Aasax as Rift languages, but finds Ehret's East Rift hypothesis insufficiently supported, and that structurally Kw'adza is instead closer to the West Rift languages. Iraqw and Gorowa are close enough for basic
mutual intelligibility. Alagwa has become similar to Burunge through intense contact, and so had previously been classified as a Southern West Rift language. Aasax and Kw'adza are poorly attested and, like Dahalo, maybe the result language shift from non-Cushitic languages. Several additional and now extinct South Cushitic languages are deduced from their influence on the Bantu languages that replaced them. Two of these,
Taita Cushitic, appear to have been more distinct from the current Rift languages than other related languages. They are similar to an earlier form of Rift, which Nurse (1988) calls "Greater Rift". There was a now-extinct member of the West Rift branch of South Cushitic that
Christopher Ehret named "Tale" (pronounced Tah-lay), and Derek Nurse called it simply "West Rift southern Cushites." The Tale Southern Cushites originated south of the
Grumeti River in the
Mara region and then expanded westward across the Mara plain, stretching their territory across north-central Tanzania (avoiding the lowlands of the southern and western lakeshore and making use of ecological zones suitable for their pastoralism south of Lake Victoria) and then expanded north into the
Kagera Region, following both banks of the Kagera river until the southern side of the
Kagera River became their northern boundary. Tale southern Cushitic territory also stretched north into the western and central highlands of
Kenya (including Mount Elgon and the Kavirondo Gulf). The Tale peoples spoke 7 or more different dialects of their languages. The Iringa Southern Cushites are another extinct South Cushitic branch that migrated to the northern parts of Tanzania's southern highlands before the first millennium AD. They are named after the
Iringa Region of Tanzania. ==Phonology==