this study aims to investigate the effect of reformulation as an indirect technique of feedback on the improvement of the use of prepositions in Iranian EFL learnesr' writing in two different context of state high schools and english private institutes and to find the extent of differences between male and female learners' improvement in the use of prepositions. the study was conducted due to the importance of the concept of feedback in language learningaccording to many scholars (Truscott, 1996; Bitchener,2005; Ellis, 2009). for this aim, 80 students from four state high schools including 40 girls and 40 boys were selected and divided into two groups experimental and control with 20 participants each and 60 language learners from one english private institute including 30 girls and 40 boys divided into experimental and control groups with 15 members each were selected as the participants and asked to do the tasks in a period of about two months. the procedureof data collection includes assigning four writing tasks with with similar pre-determined topics to the participants. reformulation was used as a feedback for the experimental group and no feedback was used for the control group. the data of the study were analyzed using ANOVA and Covariance tests. the results indicated that reformulation has no signifcant effect on the improvement of the use of prepositions in iranian male and female EFLlearners writing in both state high schools and english private institutes. it was also concluded that reformulation can neither help male and female EFL learners develop their general writing abilities in both contexts.
