This study first validates a survey on self-regulated vocabulary learning strategies. It then examines the effects on the acquisition of new second language (L2) words from a reading text of three word-focused exercise conditions: reading + marginal glosses, reading + gap-fill and reading + sentence writing. It also evaluates the extent to which any effects can be predicted by three learner variables: self-regulated capacity in vocabulary learning, L2 English proficiency level, and working memory. Data were collected from 270 Chinese EFL students. Results confirmed the validity of the survey on self-regulated vocabulary learning strategies. Learners performed the best at learning new words on the immediate post-test for the condition of reading + sentence writing, followed by reading + gap-fill and reading + marginal glosses conditions. The three learner variables predicted the effectiveness of these three conditions for vocabulary learning. Our research thus confirms the benefits of word-focused exercises, particularly sentence writing with target words, for enhancing vocabulary learning, but also highlights that learner-related variables (self-regulated capacity, L2 proficiency, and working memory) need to be considered in order to maximise the effectiveness of word-focused exercises.