摘要：This paper seeks to account for the synchronic sound changes observed in joining of noun class prefixes to nouns in Swahili, Lingala, Ciluba, and Zulu. The noun class prefixes of these Bantu languages were compared with the Proto-Bantu noun class-forms to identify sound changes the languages have undergone over time. It was observed that some sound changes did not obey synchronic rules. The aim of this study was to elaborate on diachronic rules, specifically telescopic rules, to explain why some sound changes in Bantu language evolution stand out as exceptions, giving the impression of violating the neo-grammarians’ claim about the regularity of sound change. A special focus is placed on the nasal place of articulation assimilation, which in some conditioning environments, is favourable for assimilation, but fails to occur in Swahili. The findings of this paper provide robust evidence for why the nasal phoneme of some noun classes does not assimilate in place of articulation with the adjacent neighboring segment, as is usually observed in Bantu languages. This study also attempts to explain why the noun class 9/10 nasal prefixes in Swahili assimilate in place of articulation with the following adjacent stop but not the nasal bilabial prefix of noun class 1 and 3. The findings address the concern of whether the synchronic rule of nasal assimilation in Bantu languages could account for this apparent irregularity.
