Case-Dependent Agreement in an Active–Stative Language

This paper revisits the cross-reference marking system of Mbyá Guaraní, focusing on two phenomena: object agreement using the prefix i- and its allomorphs, and absolutive cross-reference marking in converbs. The analysis demonstrates that cross-reference marking in Mbyá is sensitive to abstract Case. Building on a view of agreement as an obligatory operation whose failure does not result in ungrammaticality, this paper argues that the segment i- is an object agreement prefix, rather than part of an allomorph of an active subject agreement prefix. This marker is underspecified for person, allowing it to cross-reference 1st, 2nd or 3rd objects. The paper further argues that converbs in Mbyá Guaraní follow an absolutive cross-reference marking pattern, where only intransitive subjects or objects are cross-referenced. This pattern is shown to be consistent with cross-linguistic and historical data from the Tupí–Guaraní family. This paper’s contributions include a proposal for case-sensitive agreement in Mbyá, with active agreement prefixes realizing agreement with nominative DPs only. The analysis also emphasizes the different roles of Infl and little v as probes for person features, with little v being underspecified and not triggering cyclic expansion. The proposed framework accounts for both hierarchical cross-reference marking in independent clauses and absolutive marking in converbs, unifying these two patterns under the assumption of Case dependence of agreement.