Abstract
It is uncontroversial to suggest that in order to be successful in academic study through the medium of English as a Foreign Lanuage, a learner will need a large general vocabulary and knowledge of academically relevant vocabulary, and the latter usually means knowledge of Coxhead's influential Academic Word List (AWL). However, a large general vocabulary is likely to include all or most words from the AWL, so the contribution of knowledge of the AWL specifically to academic success is unclear. This article reports a study where the impact of word frequency in the test of the AWL is controlled, so the separate effects on grade point average (GPA) of AWL knowledge and general vocabulary size can be better understood. To this end, 61 native Arabic- speaking learners of EFL took a test of AWL and a test of general vocabulary size, and their GPAs were collected. Results indicate that general vocabulary size explains nearly 47% of the variance in GPA and that knowledge of the AWL adds an additional 11.5 % to the explanation of the variance. The discussion addresses the varying importance of general and academic vocabulary to academic success.