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…

In this dissertation, I investigated how cognitive resources as well as formal, and informal language experience impact language learning in two studies. In the first study (Chapter 2), I examined the learning of Spanish grammatical gender by Chinese international students who were studying abroad in the US. The goal of that study was to uncover…