The emergence of interior vowels and heterosyllabic vowel sequences in Ngwi (Bantu B861, DRC)

Abstract

In this article, we offer a historical account of the development of two phonemic ‘interior’ vowels, [ə] and [ɤ], and heterosyllabic vowel sequences in Ngwi, a virtually undescribed West-Coastal Bantu language spoken in the western part of the Democratic Republic of the Congo. While interior vowels phonologized due to the loss of their conditioning environment, most heterosyllabic vowel sequences come from the fission of an erstwhile palatal on-glide diphthong, itself originating in a long [–high] vowel. This origin is exactly the opposite of what has been reported for other language families such as Romance, where certain heterosyllabic vowel sequences of the *iV type evolved into diphthongs. The Ngwi data also show that phonemic interior vowels exist in languages of the Niger-Congo phylum where they had not been reported before. The historical development of heterosyllabic vowel sequences in Ngwi might have parallels in several other Bantu languages from the wider Congo rainforest area, where phonetic and phonological documentation is still embryonic.

Labial-velar stops in Sakata (Bantu C34)

“…Languages from this area all belong to Guthrie's referential B80 group, which is the most diverse within West-Coastal Bantu in terms of basic vocabulary. Atypical phonological features crosscut phylogenetic subgroups and include: large vowel systems with up to 13 vowel phonemes (Ebalantshim Masuwan 1980, Koni Muluwa & Bostoen 2019, Mfum-Ekong 1979 including interior vowels (Pacchiarotti et al 2021), diphthongisation, umlaut (Bostoen & Koni Muluwa 2014), phonologically unconditioned final vowel loss (Pacchiarotti & Bostoen 2021a), dorsal fricatives (Pacchiarotti & Bostoen 2022), and heterosyllabic sequences of mid and low vowels (Pacchiarotti et al 2021; see also Daeleman 1977, Rottland 1977, Bostoen & Mundeke 2011a.…”