In this research, we investigated whether unaccusativity affects processing
of wh dependencies, by conducting two self-paced reading experiments
involving intransitive subject relative clauses (SRCs) with unergative and
unaccusative verbs in English. Importantly, we find both an “unaccusative
subject advantage” (Experiment 1) and an “unergative subject advantage”
(Experiment 2), depending on the argument structure of the matrix predicate
(i.e., whether its surface subject is VP-external or VP-internal), and
propose that this effect arises from the argument structure of the
intransitive RC verb (specifically, the merge site of its subject) which
syntactically matches with the subcategorization frame of an upcoming main
verb.