Examining variation in the expression of tense/aspect to classify the Kikongo Language Cluster

In this article we examine variation in the expression of tense and aspect (TA) in 23 modern and two historical Bantu language varieties belonging to Guthrie’s B40, H10 and H30 groups in order to shed light on the internal classification of the Kikongo Language Cluster (KLC). We apply the Comparative Method to this specific set of morphological data to test a recent phylogenetic classification of the KLC. We identify eight widespread TA markers as shared retentions dating back to the period before the internal fragmentation of the KLC. Six of these are inherited from Proto-Bantu. Two other markers go back to Proto-Kikongoid and Proto-Kikongo. They confirm that the KLC constitutes a discrete clade within West-Coastal Bantu. We furthermore distinguish fourteen shared innovations that took place after the break-up of the last common ancestor of the KLC. These innovations provide corroborating evidence for three phylogenetic subgroups within the KLC, namely East, South and West, and for the fact that the latter subgroup falls apart in two discrete genealogical subunits. They furthermore testify to the horizontal transmission of TA features between subgroups. Such language convergence often correlates with relatively recent historical developments within the Lower Congo region and contributed to the multilayered constitution of the KLC.