This study probed the effect of L2 proficiency on the acquisition of the vocabulary items and grammatical structures in an output-first-then-input processing sequence. To this end, 105 participants were selected from two proficiency levels (high-and low-intermediate). Participants of each proficiency level were randomly divided into two subgroups so that four treatment groups were arranged. Two groups (one high-and one low-intermediate) were assigned to the output condition and went through

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... ut-input-recall procedure. The other two groups (one high-and one low-intermediate) were assigned to the non-output condition and went through input-recall procedure. The results indicated considerable effect of output-input sequence on learners" acquisition of the targeted vocabulary items and grammatical structures (p= .000). However, for the L2 proficiency level, the results of the vocabulary and grammar scores showed no statistically significant difference between the two conditions.