Corrective feedback (CF) has long been a hot topic in language education circles and has received extensive research attention. However, there is still controversy over the effectiveness of CF use and error correction in language classes. To address this discrepancy, the current study probed the effectiveness of different CF types in improving grammatical accuracy in writing. We recruited 74 female English as a foreign language students within the age range of 16-21 at an intermediate proficiency level and divided them into four treatment groups and one control group. Four feedback types were used in the treatment, namely explicit correction, clarification request, metalinguistic, and elicitation. The experimental groups' grammatical knowledge of target structures (tense, voice, and agreement) was assessed before and after CF treatments and was compared with that of the control group. The findings revealed that all feedback groups outperformed the control group, highlighting the effectiveness of CF treatment. In addition, the metalinguistic feedback group outperformed all other experimental groups, with no difference observed between elicitation and clarification request groups. Further findings and implications are discussed in the paper.