Although corrective feedback (CF) has been studied, more studies still need to be conducted on this variable to check its effects on language learning. Therefore, this study aimed to investigate the effectiveness of teachers' written and verbal CF during the formative assessment (FA) on English as a foreign language (EFL) learners' academic anxiety (AA), academic performance (AP), and attitude toward learning (ATL) in Ahvaz, Iran. Using the convenience sampling method, 76 students were chosen and divided into the experimental group (EG) and control group (CG). The EG received CF during FA, but CG was taught traditionally. After analyzing the data through descriptive and inferential statistics, the results indicated that the teachers' written and verbal CF during FA positively affected the experimental language learners' AP. In addition, the results showed that teachers' CF significantly diminished the EG's level of anxiety. Regarding the learners' ATL English, the results showed that there was a significant change in the pre-test and post-test due to the feedback received from the teacher, which means that learners' ATL enhanced remarkably. Considering the results of this study, a number of conclusions are drawn, and several implications are put forward.