Non-Verbal Predicates in Tongan

In any head-driven theory of clause structure, where clauses are some sort of verbal category, the presence of clauses without an overt verb poses an interesting puzzle. Should or can the non-verbal clauses be assimilated to verbal clauses via a phonologically-null verb, or should they be analyzed in another way? This issue has been the subject of a fair amount of research in HPSG over the last 10 years (Sag and Wasow 1999 and Bender 2001 looking at AAVE, Avgustinova 2006 looking at Russian, and Henri and Abeillé 2007 looking at Mauritian Creole). In this paper, I add another language – the Polynesian language Tongan – to the discussion, both to better understand this kind of construction cross-linguistically and to better understand the nature of Tongan clause structure. After illustrating the differences between verbal and non-verbal clauses in Tongan, I consider both constructional (phrase structure-based) and head-driven (lexical item-based) analyses for the latter kind of clause. I argue that a head-driven approach, where an element within the predicate is the head, is the best solution. However, such an analysis has to split the head’s arguments so they do not combine with the head simultaneously.