The Effect of Explicit Instruction on the Acquisition of English Verbs by Japanese Learners: Focus on the Learners’Judgment on Non-Instructed Verbs

The present study investigates whether Japanese learners of English (JLEs) properly use intransitive and transitive verbs. It is well known that adult Japanese learners of English tend to overpassivise certain types of intransitive verbs (Hirakawa 1995, Zobl 1989) and drop the object in a transitive structure (Wakabayashi and Negishi 2014). Over the years, the effect of explicit instruction in a second language (L2) has been a topic of interest, and the acquisition of English verbs by Japanese learners is no exception to this trend. In this study, we examine 1) how grammaticality judgments of English sentences differ between 2 proficiency levels, 2) whether explicit instruction affects their judgment on non-instructed verbs, and 3) whether the effects differ between 2 groups. The results show that even the lowerproficiency learners improved in terms of their judgment on intransitive verbs, after receiving brief instruction. However, we also show that larger effects were observed in the high proficiency group