Due to the typological differences between Korean's aspect system and English's aspect system in terms of progressive construction "-ko iss," learners can no doubt have difficulty acquiring and using the "-ko iss" construction in learner Korean. This dissertation investigates two main points: (i) how is the "-ko iss"…

The tendency for negation to appear early in the sentence, dubbed the "Neg-First principle" by Horn (1989:452), has been observed in the domains of typology, language contact, and language acquisition. Based on evidence from these fields, scholars have speculated about the source and universality of Neg-First biases affecting language…

Natural language is highly complex and can be challenging for some learners, yet the contribution of complexity to individual differences in language learning remains poorly understood. This poor understanding appears due to both a lack of consensus among researchers regarding what complexity is, and to on-line language research often employing…