The definition of a grammatical ‘subject’, and the properties an argument must have to be characterized as a subject is long debated (e.g., Comrie, 1975; Keenan, 1976). This thesis investigates the relationship between subjecthood, case marking, and transitivity, from both a typological perspective and from an in-depth study of the ergative Polynesian language Niuean. I present two original experimental studies of sentence processing in Niuean, which show that processing of long-distance dependencies and resolution of anaphoric pronouns is
affected by agentivity, case marking of arguments, and predicate transitivity. Coupled with formal syntactic analysis, these findings support a view in which a subject is defined as the most agentive verbal argument present in a clause, and further reveal syntactic effects of
the distribution of the case marking borne by each argument. Case distribution (known as ‘unmarkedness’ in syntactic literature) and subjecthood are argued to be two distinct factors which, together, influence how accessible an argument is in both syntactic operations and in sentence processing.Ph.D
