摘要：This study investigates the effect of teacher’s written corrective feedback (WCF) on acquisition of explicit and implicit knowledge of simple past tense by language learners. Eighty-seven Iranian beginner learners of English participated in this study. The participants were randomly assigned to three groups: focused direct WCF, focused indirect WCF, and control groups. The participants completed text summary tasks. They also took placement test, pretest narrative writing task, text summary tasks, pretest and posttest untimed grammaticality judgment test, metalinguistic test, and timed grammaticality judgment test. The results of the data analysis showed the positive effect of WCF on acquisition of explicit and implicit knowledge of simple past tense by Iranian beginner learners of English in an English as a foreign language classroom context. However, the findings of the study should be interpreted cautiously due to different factors involved in explicit and implicit acquisition of a structure and also the nature of a structure and its difficulty and complexity. The findings of the study are discussed in detail and future venues for research are suggested.
