Final Vowel Loss in Lower Kasai Bantu (drc) as a Contact-Induced Change

Abstract

In this article, we present a qualitative and quantitative comparative account of Final Vowel Loss (fvl) in the Bantu languages of the Lower Kasai region of the Democratic Republic of the Congo. We argue that this diachronic sound shift rose relatively late in Bantu language history as a contact-induced change and affected adjacent West-Coastal and Central-Western Bantu languages belonging to different phylogenetic clusters. We account for its emergence and spread by resorting to two successive processes of language contact: (1) substrate influence from extinct hunter-gatherer languages in the center of innovation consisting of Bantu B80 languages, and (2) dialectal diffusion towards certain peripheral Bantu B70, C80, H40 and L10 languages.

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

“…In this section, unless otherwise specified, the asterisk next to a segment not preceded by the label BLR refers to a form presumably present in an earlier stage of Ngwi. As happens with other WCB varieties spoken along the Lower Kasai in the DRC, Ngwi underwent final vowel loss (Pacchiarotti & Bostoen 2021). Once this diachronic sound change took place, the conditioning environment which originally triggered [ə] and [ɤ] as allophones of /i/ was lost and phonemic split arose.…”

“…If the last constituent of a NP has a F (or a HL) tone or R (or LH) tone, the spreading H tone cannot change this contour tone pattern into H or HH, as shown in ( 7)-( 11). The following are possible syllable shapes in Ngwi: CVC, VC, CV, and V. Due to the diachronic loss of final vowels (Pacchiarotti & Bostoen 2021), CVC is by far the most common. For the purposes of the present paper, however, VC and V are particularly relevant (see the historical discussion in sections 4.3.2 and 4.3.3).…”

“…In Table 6, we present a possible seriation of changes to account for the /i.a/ outcome in Lower Kasai languages like Ngwi B861 and the /ya/ outcome in Lower Kasai languages like Mpur B85e, out of protoforms with a C1V1C2V2 shape where C2 is not a N or a NC and V1 and V2 were both *a. The chronology of C2 loss and final vowel loss is based on Pacchiarotti & Bostoen (2021) In an experimental study on the heterosyllabic vs. diphthongal realizations of inherited *iV Late Latin sequences in five Romance languages, Chitoran & Hualde (2007, 55, 59) find that the general evolutionary tendency for heterosyllabic [iV] sequences to be shortened to diphthongs is inhibited when vowel sequences are found in word-initial (stressed) syllables, because they have a greater duration than vowel sequences found in non-initial (unstressed) syllables. Considering these experimental findings, the creation of heterosyllabic /i.a/ sequences in Ngwi might have been favored by the fact that a historical disyllabic word became, at some point in earlier stages of Ngwi, a monosyllabic CVː stressed word.…”

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.…”