Not covertness but definiteness matters: Two types of covert correlate in Sluicing

This paper investigates into Sluicing without an overt correlate expression in the antecedent clause. We argue that, contrary to appearance, this type of Sluicing in fact has a covert correlate expression in the antecedent clause, and that this covert correlate expression falls into two sub-types: one is an implicit argument, and the other is a null category derived by deletion. Since both an implicit argument and a null category are an object/complement of apparently intransitive verbs, we suggest that they are licensed by two different sets of verbs. We show that an implicit argument correlate is indefinite, whereas a null category correlate is definite, which accounts for the contrast between them in regard to island sensitivity.