eng Rovedar Journal of Contemporary Language Research 2980-8065 2023-03-25 2 1 9 15 17 Shirin Kamali Khalavi 0 https://orcid.org/0009-0006-1165-540X Mitra Zeraatpishe 0 https://orcid.org/0000-0001-7918-3062 Department of English, Mashhad Branch, Islamic Azad University, Mashhad, Iran Introduction: Recent years have witnessed a growing interest in investigating L2 English productive and receptive vocabulary knowledge in writing. Previous inquiries focused heavily on the pedagogical effects of teaching vocabulary on writing. A less investigated area is learners’ lexical competence involvement in the complicated writing process regarding their subcomponents. To bridge the research gap, the present study examined the alleged relationship between the elements of vocabulary depth (collocation and synonym) and the writing skill’s subcomponents (vocabulary use, content, and organization). Methodology: Thirty intermediate English as a foreign language (EFL) learners’ writing scores on the Preliminary English Test were compared and correlated to the depth of vocabulary knowledge (DVK). The writing texts were given a holistic score, and several lexical measures were calculated. Results: The results indicated significant relationships between DVK and writing, synonym and vocabulary use, synonym and content, collocation and vocabulary use, and collocation and writing scores. The result of multiple linear regression revealed the double impact of collocation as a predictor of writing scores. Conclusion: The findings showed the predictable pedagogical value of practicing collocation in EFL writing enhancement. https://jclr.rovedar.com/index.php/JCLR/article/view/15 Collocation Depth of vocabulary knowledge Organization Synonyms Vocabulary use Writing skill