Verbal Number in Wari’

Wari’, a Chapacuran language spoken in Western Brazil, has a large number of verbal pairs that alternate between singular and plural forms, most typically according to the number of participants involved, but also according to emphasis. We document the semantics and morphology of these alternating pairs, some of which are suppletive and some of which have lexically restricted morphology, and compare the verbs recognized by modern speakers with those reported in the previous literature. We compare Wari’ with other Chapacuran languages and provide historical sources for morphological processes and the etymology of some singular/plural roots. Our analysis shows that Wari’ has an unusually large inventory of these verbal pairs and typologically rare features, such as alternation based on the plurality of the transitive subject and atypical verbal semantics.