Чадские языки
As is common in Chadic languages, the principal vowel is the low central vowel /a/; where there is no underlying V-slot, an epenthetic ‘zero vowel’ is inserted. Despite the limited distribution of the other vowels, /i, u, e, o/ have emerging phonological status. However, as has been observed in other Chadic languages, certain contrasts are productive only word-finally, excluding the sub-lexicon of loan words.