The role of cognitive individual differences and learning difficulty in instructed adults' explicit and implicit knowledge of selected L2 grammar points: A study with Mexican learners of English

This study explored the relationship between implicit and explicit knowledge of 13 second language (L2) English grammar points and the relationship of each type of knowledge with language learning aptitude and working memory capacity in 90 Mexican learners of L2 English at three different levels of proficiency (Level 5, Level 7, Level 9). An elicited imitation test and an oral narrative test were used to measure implicit knowledge, and a metalinguistic knowledge test was used to measure explicit knowledge. With respect to language learning aptitude and working memory, the former was operationalised by the LLAMA test, and the latter by the backward digit span test. With regard to the relationship between implicit and explicit knowledge, implicit knowledge correlated positively and weakly with explicit knowledge while an analysis by grammar point showed a non-significant negative correlation approaching significance between implicit and explicit scores. These results indicate that learners found some grammar points easy in terms of explicit knowledge and other grammar points easy in terms of implicit knowledge, and vice versa. Learners’ language aptitude and working memory did not significantly predict explicit or implicit knowledge of the targeted difficult and easy grammar points for the cohort of participants as a whole. Another analysis by level group (Level 5, Level 7, Level 9) indicated that the cognitive variables did not significantly predict explicit knowledge of easy or difficult grammar points. However, with respect to implicit knowledge, working memory significantly predicted implicit knowledge of easy grammar points in Level 5, and language aptitude marginally predicted implicit knowledge of difficult grammar points in Level 5. Overall, the findings support the view that language aptitude and working memory are better predictors at lower levels of proficiency. The findings of this study contribute to researchers’ understanding of the distinction between implicit and explicit knowledge and the relevance of language aptitude and working memory at different levels of proficiency.