The present study was an attempt to discover the effects of explicit written vs. explicit oral corrective feedback on Omani part-time vs. full-time College students’ accurate use and retention of the passive voice. The participants consisted of the students of six intact classes, i. e. three part-time and three full-time, who took an Oxford Quick Placement Test (OQPT) as a general proficiency test. Following the proficiency test, the participants took three similar, but not identical, tests on the target structure as pretest, posttest and delayed posttest. In response to the errors made in the pretest, the experimental groups received explicit written and explicit oral corrective feedback in their treatment phase whereas the control groups did not receive such explicit written or explicit oral feedback. The accuracy of the use and retention of the passive voice was measured by a posttest and a delayed posttest. The results indicated a significant difference between the pretest performance of the experimental groups and their performance in the posttest and the delayed posttest. Similarly, the results showed a significant difference between the performance of the experimental groups and that of the control groups in the sense that the experimental groups outperformed the control groups. In addition, there was a significant difference between the performance of the part-time students and that of the full-time students in that the part-time students outperformed the full-time students. Finally, there was no significant difference between the experimental groups’ performance on the posttest and their performance on the delayed posttest.