Phonology

The phonology of Proto-Central Chadic consists of 31 consonants, three vowels and a morpheme-level palatalization prosody.

The three vowel phonemes are /a/, /i/ and /ɨ/.

In present day Central Chadic languages, the palatalization prosody has two basic types. The first is the vowel palatalization prosody, which fronts the vowels in the morpheme. The second is the consonant palatalization prosody, which palatalizes one or more consonants in the morpheme, primarily the laminal consonants. There is considerable variation in how the palatalization prosody is realised between different languages. In many cases there are elements of both the vowel prosody and consonant prosody types. In Proto-Central Chadic, the palatalization prosody was probably of mixed type.

The consonant phonemes include a set of labialized velar consonants. In many of the present day languages which have the consonant palatalization prosody, the labialization component has transferred from a velar to a labial consonant in several words, leading to the creation of a set of labialized labial consonants. Likewise, in present day languages which have the vowel palatalization prosody, the labialization component has been reanalysed as a vowel labialization prosody, causing the back-rounding of the vowels in the morpheme.

The consonantal system of Proto-Central Chadic is as follows: