In the Oceanic language Äiwoo, verb forms can achieve rather extensive complexity, including causatives, applicatives, voice markers, multiple person marking constructions, aspectual/modal affixes and clitics, etc. The main object of research of this thesis is precisely the morphosyntactic complexity of Äiwoo verb forms. I inquire into issues of affix order and the internal structure of these forms: which affixes are there, what is their behaviour, why are they in the order in which we find them, and how can their organization best be described and accounted for? Do complex verb forms have inner hierarchical structures, or are they built differently, e.g. following an arbitrary linear template, where different morphemes are assigned each to a specific slot? I argue that the behaviour and distribution of almost all morphemes occurring in Äiwoo verb forms can be accounted for on the basis of independent syntactic and semantic principles – apart from a single one. The present work aims to be of interest to linguists who place themselves both in the typological/ functionalist tradition and the formalist/generative one. The questions outlined above have typological significance, as they inform us about what constitutes a possible morphosyntactic (verbal) system, and how complex words can be built; moreover, complex morphosyntactic structures such as these are better studied in e.g. North-American languages, known for their polysynthetic character, and less in Oceanic languages. In order to answer to those questions, I have developed a morphosyntactic model of the Äiwoo verb (and clause) within a generative minimalist framework, which incorporates notions from Distributed Morphology. This thesis constitutes the first study of a language of this geographical region and phylogenetic subgroup in a generative framework.