The main objective of this study is to determine the actancy system (ergativity or accusativity) of Proto Central Pacific, and to determine how this system developed in its daughter languages, Fijian and Rotuman, which are accusative, as well as in the Polynesian languages, some of which are ergative. It is shown that an ergative system has to be reconstructed for Proto Central Pacific, based on the presence of two sets of clitic pronouns (Genitive and Nominative) used for the core arguments of transitive constructions. A set of independent pronouns is also reconstructed. These pronominal forms are shown to be reflexes of Proto Malayo-Polynesian reconstructions.
The process by which the ergative parent language changed into some of its accusative daughter languages is illustrated.
The following points in this work may be of particular interest:
1) a description of clear cases where the actancy systems change from ergative to accusative;
2) an illustration of how syntactic, phonological, morphological, and/or lexical changes are synthesised;
3) typological descriptions of three Central Pacific languages, namely Rotuman, Fijian, and Tongan, applying Lexicase Dependency
4) a modification to the currently accepted subgrouping hypothesis for the Central Pacific group.