This talk highlights the processing of wh-dependencies by native English speakers and Mandarin Chinese-speaking learners of English. Wh-dependencies involve a long-distance relationship between a fronted wh-word (e.g., who) and the position in the sentence where it originated, called a gap site. The examination of wh-dependency resolution presents an interesting test case for whether or not grammatical knowledge is used online, because in languages such as English, wh-movement is constrained such that extraction is only possible from certain positions and is barred from other positions, called islands (Ross, 1967). In examining whether native speakers and second language (L2) learners are sensitive to island constraints online, this study tests predictions of prominent theories in SLA which argue that adult learners are unable to utilize abstract grammatical information during processing (e.g., Clahsen & Felser, 2006).