摘要：According to option-based conceptualizations of Focus on Form instruction (FonF), put forward by Ellis (2012), in EFL contexts employing mother tongue can be a viable option to be embedded in FonF instruction. This study investigated the use of the mother tongue in FonF instruction and its possible effect on language learners’ written performance. To this end, 100 language learners at elementary and intermediate levels of proficiency, in four groups of 25, participated in this study. Two experimental groups received four FonF instructive sessions mediated by their mother tongue, and for the other groups, no L1 use was allowed. After the instruction, the participants were required to take tests in which the intended grammatical structures were supposed to be produced in a written format. The results showed that the learners receiving the L1-mediated instruction outperformed their counterparts. The findings were discussed psycho-linguistic factors involved in language data processing, and they can be useful to language teachers in the EFL contexts regarding making decisions about using L1 in L2 language teaching contexts.
