The purpose of the present study was to explore if providing recast and prompt would have different effects on the grammatical development of Iranian learners of English. In other words, the study investigated the effect of corrective feedback on learners’ grammatical achievement. After administering a proficiency test, forty-five participants out of sixty were selected from the intact classes at a language institute in Ahwaz. These forty-five participants were randomly assigned to three groups namely, prompt, recast and no-feedback group or and control group each comprising of fifteen participants. Picture description tasks, referred as focused tasks (Ellis, 2012) were used as treatment. Two pen-and-paper tests were used as data collection tool. One was a grammatical judgment test and the other was a metalinguistic knowledge test. Data analysis through one-way ANOVA and Tukey test revealed significant differences between recast and prompt groups (p<.05). The results also showed that though both recast and prompt enhance the grammatical development of the learners, learners in prompt group achieved more than those in both recast and control groups. The results would benefit those teachers dealing with grammar instruction and error correction techniques. Moreover, teacher educators can use the findings of this study in their teacher education courses for pre-service or in-service teachers.
