Sujeewa Hettiarachci successfully defended his dissertation on June 22, and has started a job as faculty member in the English Department at the University of Sri Jayewardenepura, Sri Lanka. Sujeewa is currently teaching Linguistics and TESL courses, and he has also been appointed as a co-coordinator to design and start a Masters program in Applied Linguistics and TESL. Congratulations, Sujeewa! Information about Sujeewa's dissertation is given below.

 

Syntactic Competence and Processing: Constraints on Long-distance A-bar Dependencies in Bilinguals

Chair: Acrisio Pires. Other committee members: Julie Boland, Sam Epstein, Julia Herschensohn

This dissertation investigates the syntactic competence and processing of A-bar dependencies by Sinhala native speakers in their L2 English. The specific focus is on wh-dependencies (wh-questions and relative clauses) and topicalization, given that these phenomena are syntactically distinct across the two languages. Presenting novel experimental data from a series of planned experiments, the study reevaluates the predictive and explanatory power of two recent hypotheses in generative second language acquisition —the Feature Interpretability Hypothesis (FIH) and the Shallow Structure Hypothesis (SSH)—which concern the kind of ultimate attainment possible in post-childhood L2 acquisition.

The first part of the dissertation is a re-evaluation of the FIH, in particular the claim that post-childhood L2 learners fail to develop native-like underlying mental representations for the target language syntax because their access to UG is restricted in the domain of uninterpretable syntactic features. Two experiments (Grammaticality Judgment and Truth-value Judgment tasks) were conducted with thirty-eight Sinhala L1/English L2 speakers and a control group of thirty-one English monolinguals. Contra the predictions of the FIH, our results show that highly proficient L2 speakers are capable of acquiring native-like syntactic competence even in those domains where L2 acquisition involves the mastery of a new uninterpretable feature. The fact that these L2ers have been able to overcome a Poverty of the Stimulus problem, imposed by both their L1 syntax and L2 input, implies that full access to UG is available in post-childhood L2 acquisition.

The second part of the dissertation re-evaluates a tenet of the Shallow Structure Hypothesis that in real-time processing of complex target language syntax, L2 speakers fail to build detailed, hierarchically complex syntactic representations, but instead over-rely on non-structural information such as lexical semantics and contextual cues, unlike native speakers of a target language. The results from two Self-paced Reading experiments with thirty-six bilinguals and thirty-nine monolinguals show that advanced L2 learners are indeed capable of building complex native-like syntactic representations during their real-time comprehension of the target language. Thus, the study concludes that neither the FIH nor the SSH can be maintained in the experimental L2 acquisition domain investigated in this dissertation."