Amahuaca ergative as agreement with multiple heads

The mechanisms underlying ergative case assignment have long been debated, with inherent and dependent theories of ergative case emerging as two of the most prominent views. This paper presents novel data from the Panoan language Amahuaca, in which ergative case is sensitive to the position of the transitive subject. The interaction of movement and morphological case assignment in Amahuaca cannot easily be captured by current inherent or dependent case theories. Instead, I argue that a view of ergative case as exponing agreement with multiple functional heads (specifically v and T) is able to account for the Amahuaca data, while incorporating key insights from both inherent and dependent case theories of ergativity. I further demonstrate that this approach that takes case to be the exponence of multiple features is able to be extended to account for elements of the language’s case-sensitive switch-reference system as well as its focus-sensitive nominative marking. The Amahuaca data thus suggest that ergative case can be viewed as a feature bundle, rather than a single case feature, and that morphological ergative marking arises as the exponence of structural relationships between multiple heads and a nominal.