Proto-Chadic reconstruction and Afroasiatic vowel system typology

Abstract The reconstruction of the Proto-Chadic ( PC ) vowel system has hitherto been considered impossible. Proposals covered one (*a), two (*a, *ə), three (*a, *i, *u) and four (*a, *ə, *i, *u) vowels. The one-vowel solution gains support by evidence from mainly the languages of the Central Chadic branch, together with the notion of palatalisation and labialisation prosodies, which create particular ‘colourings’ for vowels and consonants in phonetic surface realisations and have been discovered to operate in all branches of the family, but to very different extent. Based on new insights into the phonological history of Central Chadic (Wolff 2022, forthcoming), at variance with Gravina (2014), and referring back to a typology of Chadic vowel systems suggested by Schuh (2017), we can now tentatively delineate the development from a minimal vowel inventory */a/, *[ə] in PC to vowel systems of between one and 15 (short and long) phonemic vowels in modern Chadic languages. Diachronic vowel-system typology in Chadic allows a critical review of received wisdom concerning vowel systems elsewhere in Afroasiatic, potentially touching on issues pertaining to the internal sub-classification of the phylum. At least the vowel system of Tashelhiyt (Berber) corresponds in essential details to the PC minimal vowel system, a non-trivial observation that raises questions concerning genetic heritage, language contact, and/or areal innovation.