L2 acquisition of definiteness in Japanese floating numeral quantifiers

This study investigates the second language (L2) acquisition of a constraint on definiteness in Japanese floating numeral quantifiers (NQs) by native English and Korean speakers. The constraint arises because of the specific structural relation between a floating NQ and its associated noun, resulting in an obligatorily indefinite interpretation. The indirect – or, covert – encoding of definiteness in this structure allows investigation of predictions based on the cline of difficulty proposed by Cho and Slabakova (2014), whereby L2 acquisition of a covert property may be facilitated if the first language (L1) expresses the relevant feature overtly. English is such a language, having overt morphology to express definiteness, whereas Korean has floating NQs that are obligatorily, and covertly, indefinite, as in Japanese. Sensitivity to definiteness in Japanese floating NQs was measured using an acceptability judgement task. Although both L1-Korean and L1-English speakers of Japanese showed sensitivity to the constraint at group level, follow-up analyses suggested that the Korean group had more consistent knowledge. We argue that the complexity of the acquisition task – which was greater for the English-speakers than the Korean-speakers – played a bigger role in attainment than overt versus covert encoding of the relevant feature in the L1.