This experimental study investigated the impact of explicit and implicit feedback on acquiring Arabic grammar for second learners. The participants were forty-five lower-intermediate male participants studying Arabic as a second language in a Saudi Arabian language institution. All participants were equally divided into three groups; the explicit group received metalinguistics feedback, the implicit group received clarification request feedback, and a control group was instructed on the target structure but received no feedback or activities. The study targeted the Arabic past tense structure. All participants took part in two communicative-based activities, a vocabulary organization task and a picture storytelling task. In addition, all groups completed three tests, a pre-test, a post-test, and a delayed post-test, and each test involved two sections, a timed grammatical judgment test (GJT) and an untimed multiple-choice test. Data analysis was conducted using One-Way ANOVA and TUKEY tests and was validated using T-tests. There were several meaningful findings. First, interactional feedback played a beneficial role in L2 Arabic grammar acquisition, and both feedback groups outperformed the control group in the post-test and the delayed post-test. Second, while the explicit group outperformed the implicit group in the post-test, no differences were detectable on the delayed post-test. In conclusion, the study affirms the benefit of using interactional feedback, form-focused instruction, and communicative-based activities investigated by earlier studies (Ellis, 2003; Lyster & Saito, 2010) to help provide students with effective feedback. The study is one of the first research conducted to explore the effect of feedback on Arabic second learners, and more research will be needed to extend and more fully explore these results. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]