In this thesis, I propose a syntactic structure for verbs which directly encodes their event complexities. I present a model that is 'internalist' in the Chomskyan sense: Aktionsart properties of predicates are not a real-world affair, but the interpretation of a mind structure. For this purpose, I base my proposal on the Dimensional Theory of Uriagereka (2005, forthcoming). Syntactic constructs are in this view the results of operations that create increasingly complex objects, based on an algorithm that is homo-morphic with the structure of numerical categories.

 First, I propose that Aktionsart can be read off from structural complexities of syntactic objects and their associated 'theta-roles'. Specifically, I present the SAAC Hypothesis: Syntactic complexity in a verb is reflected in the number of syntactic arguments it takes.  This approach, within the confines of the Dimensional Theory, results in an emergent 'thematic hierarchy': Causer > Agent > Locative > Goal > Theme.  I test the accuracy of this hierarchy and concomitant assumptions through paradigms like the control of implicit arguments, selectional properties of verbs, extractions, aspect-sensitive adverbials, etc. 

 Second, I argue that the verbal structure I propose is syntactically and semantically real, by extending the proposal in Lasnik (1999) on VP ellipsis from inflectional to derivational morphology.  I discuss two contrasting methods of morphological amalgamation in English and Japanese, executed in  Syntax and PF, respectively.  This demonstrates a tight network of entailment patterns that holds of verbs, derived crucially from the architecture I argue for. 

 Third, an analogous point is made through the structural positionings of causative and inchoative derivational morphemes in Japanese.  There, each order of structural complexity has a profound impact on the class of eventualities a derivational morpheme can describe.  'Dimensional talks' are observed between certain derivational morphemes, which presumably find their roots in operations of the computational system within the Dimensional Theory.  I show that the verbal structure in Japanese reflects directly an underlying bi-clausality that I argue for, in terms of derivational morphemes, further supporting a natural mapping between syntax and semantics.

 This is, in the end, an attempt for a 'Minimalist' theory of Aktionsart.