This quasi-experimental study, using a pretest-treatment-posttest-delayed posttest design, investigated the effects of two comprehensive corrective feedback strategies: direct corrective feedback (DCF), and metalinguistic explanation (ME) on L2 learners' written syntactic accuracy. The participants were 90 Turkish EFL learners. After ensuring their homogeneity in terms of L2 proficiency using Oxford Quick Placement Test, they were assigned to three groups: DCF, ME, and No Feedback (NF). The treatment/control period lasted for five weeks, during which the experimental groups wrote an argumentative essay in class, received the unfocused feedback, and revised their corrected text. The participants in the NF group were provided with feedback only on content, orthography, and organization, but not on grammatical errors. Results of the posttests and delayed-posttests (after a two-week interval) revealed that both experimental groups significantly outperformed the NF group; however, no statistically significant difference was found between the DCF and ME groups. Pedagogical implications are discussed in the paper.