This study investigates how working memory (WM) capacity and L2 linguistic knowledge affect L2 literal and inferential reading comprehension, considering the presence or absence of background knowledge. Eighty upper-intermediate to advanced adult English learners participated, completing tasks to assess WM capacity, background knowledge, L2 linguistic knowledge, and reading comprehension (both literal and inferential). Stepwise regression analyses revealed that WM capacity had a stronger influence on both literal and inferential comprehension when background knowledge was absent. For literal comprehension, L2 linguistic knowledge was the sole predictor when background knowledge was present, while WM capacity dominated in its absence. Inferential comprehension was consistently predicted by WM capacity, regardless of background knowledge. These findings indicate that WM capacity and L2 linguistic knowledge influence L2 reading comprehension differently depending on background knowledge and the type of comprehension. Implications include incorporating WM training into L2 reading instruction and employing diverse WM assessment methods to measure WM independently of L2 linguistic proficiency.

The purpose of the current study was to explore the effects of background knowledge, time pressure, and involvement on reading comprehension. One hundred and twenty college students read three passages and answered comprehension questions in eight different experimental conditions: activated vs inactivated background knowledge, with vs without time pressure, and high vs low involvement. The results showed main effects of background knowledge and involvement on reading comprehension, indicating essential roles of background knowledge in facilitating the processes of reading comprehension in Korea’s EFL educational contexts. In addition, the study found an interaction effect of background knowledge and time pressure on reading comprehension. Pedagogical implications are suggested.