Split case marking and constituent order in Nilotic languages

This paper presents a survey of split case marking across the Nilotic languages of East Africa. Expanding on König’s (2008) original insights, the survey is set within Chappell and Verstraete’s (2019) typology on alternations and optionalities in case marking, taking into account all accessible descriptions. It confirms the prevalence – and traces the extent – of a construction-based split, whereby only postverbal A (split ergative) or S/A (marked nominative) arguments receive case marking. Split ergativity is overall very rare; case is marked morphologically and the languages have a default OVA order. Marked nominative systems are more common; tonal inflection is the main marking strategy, and the default order is typically verb-initial. Languages without case marking have the default orders AVO or AOV, and do not have postverbal S/A arguments. The survey furthermore reveals an interaction with referent-based splits for some languages (where postverbal S/A arguments are obligatorily case-marked if they are animate, highly agentive and/or definite), and assembles all available information on factors that condition the construction-based split. On the basis of this survey and preliminary corpus-based investigations, we suggest that the concept of discourse prominence opens up a fruitful line for future research.