In this short article I try to present a taxonomy of sources of difficulty, in particular complexity. I emphasize how these factors interact with each other and with individual differences and treatments, before illustrating some of these interactions and the methodological issues involved in studying them with examples from the empirical studies…

Numerous studies have demonstrated that native Mandarin speakers have pervasive difficulties processing L2 English agreement morphology. However, less is known about the lexical and morphological cues that may modulate Mandarin speakers' sensitivity to English number agreement. To investigate this, we examined subject-verb agreement processing in…

This article draws on an approach that conceptualizes L2 learning difficulty in terms of implicit and explicit knowledge. In a study with first language Mexican Spanish university-level learners (n = 30), their teachers (n = 11), and applied linguistics experts (n = 3), we investigated the relationship between (a) these groups' difficulty…

This study investigates the relationship between foreign language aptitude and the learning of two English structures defined as easy or difficult to learn. Using a quasiexperimental design, 66 secondary-level learners of English as a foreign language from three intact classes were provided with four hours of instruction on the "passive"…