Abstract
The Functional Grammar Approach is a modern linguistic perspective that views language as a tool for communication rather than merely a set of formal rules. According to Halliday, language serves three main functions: the ideational function (expressing ideas and experiences), the interpersonal function (building social relationships), and the textual function (organizing messages in a coherent way). This approach represents a significant shift in linguistic studies, focusing on meaning, context, and communication, and offering a deep understanding of how language functions in everyday life. This study examined the effectiveness of the Systemic Functional Grammar (SFG) approach in enhancing academic writing skills among EFL postgraduate students. An experimental design was employed to compare 25 students’ performance in pre- and post-tests, and adopting content analysis to reveal which skills were truly improved. The results revealed a statistically significant improvement in students’ writing after the implementation of the SFG approach. Furthermore, content analysis of students’ texts showed noticeable progress in vocabulary use, organization, and cohesion. The findings also highlighted the important role of thematic structures, particularly theme and rheme, in improving coherence and textual organization. These results support the view that grammar should be taught as a functional and meaningful resource rather than a set of mere rules. Based on these findings, the study recommends integrating authentic learning environments, adopting implicit grammar teaching strategies, and promoting critical thinking to further develop students’ writing competence.