A typology of valence-changing mechanisms and related verb modifications in Northern Chaco Mocoví (Guaycuruan, Argentina)

This dissertation examines verb modifications that change the verb valence and the pragmatic status of core arguments in Northern Chaco Mocoví (Guaycuruan), one of the northernmost points of the Mocoví dialectal chain in Argentina. Combining natural speech and elicited data, I analyze four verb modifications which operate mainly on the status of subject arguments but also affect objects. First, I focus on the class of three morphological markers that add a new subject argument to different classes of predicates and the analytic strategy to express the causing event of a range of verb types. Second, verb modifications defocusing the subject argument are addressed. Then, I concentrate on a verb derivation that highlights the subject's activity, and consequently reduces the discourse prominence of the object argument. Finally, I analyze a verb modification expressing mutual interaction of participants, which can also function as a valence-reducing mechanism. The study of these different verb modifications highlights the interaction between verb valence classes and the specific way in which Northern Chaco Mocoví organizes the verb lexicon, showing the preferred patterns to increase and reduce the basic valence pattern in the language. This work also contributes to a better understanding of the complex system of argument expression and the constraints that regulate argument indexing. Furthermore, this dissertation expands the typology of valence alternations by showing cross-linguistically relevant correlations between verb markers and types of valence modifications.