There has been an increasing attention to written corrective feedback (WCF) and its potential effectiveness in recent years. This paper examines the roles of direct versus indirect WCF in fostering learners’ written and oral accuracy across language proficiency. A quasi-experimental design was adopted to conduct the study. Seventy-six pre-intermediate and upper-intermediate EFL learners were randomly assigned into six groups (four experimental and two control groups). In the experimental group, a series of pictures were used as prompts for writing tasks in the treatment sessions, and pre-, immediate, and delayed posttests were used to measure written and oral accuracy. According to the results, WCF, regardless of the type, was facilitative in developing learners’ both written and oral accuracy, which was a manifestation of implicit knowledge. The results also revealed that the proficiency level played a key role in determining which type of CF was more beneficial. While the pre-intermediate learners benefited more from direct CF, the upper-intermediate group improved more as a result of indirect CF treatment. This study calls for more informed decisions by L2 teachers in the correction of written errors considering that it improved L2 learners’ oral accuracy
