This dissertation investigates the structure of clauses and how key subparts of them – the arguments of their predicates – are realized in the Polynesian language, Tongan. The leading proposal of this work, running through the analyses of all phenomena, is that Tongan can be analyzed with less syntactic structure than has previously been proposed by others working on Polynesian languages. The framework I make use of – Sign-Based Construction Grammar (SBCG) – is multi-factorial; it spreads the analytical load among parallel (but related) constituency, syntactic valency, and semantic data structures. This dissertation, drawing on extensive fieldwork data, shows that Tongan is better analyzed in terms of minimal hierarchical structure and that a multifactorial approach offers a more comprehensive and accurate understanding of Tongan morphosyntax than previous accounts.

Issues of clause structure are the focus of the first half of the dissertation. The region of verbal clauses that includes the verb and its dependents is analyzed in terms of a “flat” structure, while the predicate and arguments in non-verbal clauses are assigned more hierarchical structure. This difference derives from different argument realization constraints on the predicates in these clauses: verbs and prepositions, respectively. The combination of an initial Tense-Aspect-Mood word and one of these verbal or non-verbal constituents usually completes the construction of the basic Tongan clause.

A discussion of argument realization phenomena constitutes the remainder of the dissertation: the subject clitics, the cross-predicate distribution of case, the structure and distribution of noun incorporation, and the preposition-like and applicative constructions with the instrumental particle `aki. These investigations provide evidence against a syntactic treatment of argument realization in Tongan, and for a treatment centered around lists of potential dependents of predicates. These lists allow hierarchical structure to be minimized, because they provide another locus for grammatical interactions. This locus avoids the complications that arise on other approaches where the interactions are derived entirely within the phrase structure. Yet, these lists allow direct generation of the phrasal structures, licensing the structure that is necessary for an account of the syntax of Tongan.