Although various features of collaborative writing, like those involving translanguaging, have been noted to be potentially beneficial in enhancing writing, there is a dearth of systematic research exploring the effects of collaborative writing on writing precision and elaborateness in the context of EFL. The present research attempts to examine how translanguaging and various task types affect co-constructing passages in the EFL setting. Specifically, it examines the impact of translanguaging and task types on EFL students’ collaborative writing and how these factors influence the quality of written texts in terms of syntactic complexity , accuracy, lexical diversity, fluency . The study was conducted involving 28 Iranian EFL learners divided into two groups of seven pairs in each one. There were both male and female students aged between 18 and 25 years. The study used quantitative approach by comparing the writing accuracy and complexity of the co-constructed texts by EFL learners. Two task types, composition writing and picture-prompted description, were selected as the instruments in the study based on which the participant were to co-construct a written text. The data were collected during six sessions. It has been found that the tested form of translanguaging and the types of the tasks used in the study have positive effects on enhancing the accuracy and complexity of written products. When students were required to work in pairs to engage in a writing assignment, it might be effective if learners switch between their first and second languages. This point implies that it could be helpful for learners to use what might be referred to as complex linguistic and cognitive tasks. These results are significant in understanding instructional methods in EFL environments, with particular emphasis on translanguaging and task type.
