This paper studies Korean L2 English learners’ responses to negative polar questions (NPQs – i.e., negative yes-no questions), focusing on the differences between EFL learners (those learning English as a foreign language in Korea) and ESL learners (those learning English as US residents). The paper first considers differences in the syntax and semantics of Korean and English NPQs, differences that may lead to misinterpretations when questions are translated from one language to the other. The paper then describes a series of experiments comparing Korean EFL and ESL learners’ responses to English polar questions, focusing on measuring participants’ response times (RTs) and unexpected responses (UERs) to distinct classes of these
