The nature of variable sensitivity to agreement violations in L2 English

This study focuses on the nature of variable sensitivity to violations of subject-verb number agreement in L2 English by examining Japanese-speaking learners’ performance in a self-paced reading task. The results of the experiment indicated that the learners were insensitive to agreement violations deriving from omission of 3rd person singular (3sg)-s, but were highly sensitive to violations deriving from overuse of 3sg-s. Their sensitivity to this type of violation, however, turned out to be non-categorical in that it was adversely affected by an adverb intervening between the subject and the verb. These results are interpreted to indicate that intermediate learners’ implementation of subject-verb agreement is not based on Agree operations, but on the Vocabulary entry for /s/ which is sensitive to the condition of the string of co-occurring terminal nodes as proposed by Hawkins and Casillas (2008).