The completion mode (individual, collaborative) of the tasks and the conditions under which these modes are performed have been reported to play an important role in language learning. The present study aimed to investigate the effects of employing text editing tasks performed both individually and collaboratively, on the achievement of English grammar under explicit and implicit learning conditions. Eighty-four English learners participated in this study. Some text editing tasks were developed regarding the target grammatical structures and presented to the participants under the explicit and implicit learning conditions. Their gram- mar achievement was operationalized through a multiple-choice recognition test. The results indicated that there was no significant difference between the effect of implicit and explicit conditions when editing tasks were performed individually, but collaborative completion of this task resulted in a significantly higher grammar achievement under explicit condition than implicit one. The comparison of the individual and col- laborative performance of the task, under implicit and explicit conditions, revealed no significant difference under implicit condition. Collaborative completion of the task under explicit condition, however, proved to yield higher levels of grammar achievement when compared with the individual mode of performance. پرونده مقاله