Discourse-linking in advanced L3 English: Testing the Interface Hypothesis

This study tests the Interface Hypothesis in the field of L3 acquisition. The learners are L1 Arabic-L2 French adults at the intermediate and advanced levels in L3 English. A forced multiple-choice written task tests non-d-linked and d-linked wh-questions, representing narrow syntax and the syntax-discourse interface. The intermediate learners of L3 English used the two constructions interchangeably regardless of the context. Comparatively, the advanced L3 learners diverge from the English native speakers on the syntactic construction but converge with them on its interface variant. They show sensitivity to the discourse-appropriateness distinction between d-linked and non-d-linked questions, contra the predictions of the Interface Hypothesis. We maintain that external interface properties such as d-linking are not necessarily destined for permanent representational deficit in the L3.