The stability of UG principles in second-language acquisition: evidence from Japanese

Second-language acquisition is subject to great variation in terms both of ultimate attainment and of the developmental process itself. This paper explores the possibility that at least part of this variation is due to a lack of stability in learners' access to UG. I report here on a limited-scope longitudinal study that examines this matter. The study focuses on a UG principle that prevents overt pronouns from having quantified NPs as antecedents in languages (such as Japanese) that have null pronouns. Data was collected from a group of 29 English-speaking adults learning Japanese as a second language at two different times. For both sessions, the L2 learners as a group exhibited a statistically significant difference in their interpretation of null and overt pronominals when there was a quantified antecedent. These results clearly suggest access to UG. However, when the performance of individual L2 learners is examined, one can discern a striking inconsistency across the two sessions. I propose that this inconsistency reflects an instability in the relevant UG principle that results from its relatively infrequent use in the course of second-language acquisition