This dissertation addresses two questions: (a) how do we explain the limited set of argument structure types? and (b) how do lexical structures relate to syntactic structures? My work is situated within the approach of Hale and Keyser (2002, henceforth H&K), whose purpose is to ascertain the role that structural factors play in the behavior of lexical items.
As for the first question, H&K argue that argument structures are restricted by the combination of primitive lexical categories defined solely by structural properties. I point out that the restrictive power of this theory is undermined by allowing unrestricted recursive combination of such primitive units. By restricting this type of lexical recursion, this problem disappears.
As for the second question, I argue that two adicity-changing processes, transitivization and detransitivization, are key to understanding the relation between lexical and syntactic structures. I investigate these processes in Catalan and Spanish. I argue that there are two types of verbal affixes: one plays no role in the argument structure of the verb (but refers instead to its aspectual properties), while the other is responsible for the aforementioned processes. I argue that the affixes of the second type correspond to a functional category that bridges over from lexical to syntactic structures. After identifying these two types of affixes, I re-analyze some data (from O'odham, Navajo, Miskitu, Ulwa, and Yaqui) that H&K find problematic.
Finally, I address an important extension of H&K's theory, the "manner index". Such index is either proximate (bound by the internal argument), or obviative (bound by other than the internal argument). In H&K's theory, the type of index associated with the root determines a particular structure, which in turn determines the behavior of the corresponding verb. By breaking the determination relation between index and structure, I derive two typologies. First, I obtain a four-way paradigm by combining the structural type ("put"/"get") and the index type (obviative/proximate). Spanish prepositional verbs present the predicted patterns. Second, I account for two alternations: unergative-unaccusative in Italian, and unergative-transitive in English. Given the explanatory power of the obviative/proximate index, I conclude that it is a welcome addition.
