Developing proficient ESP writers: an in-depth exploration of cohesive devices in vocational education

Cohesive devices play a vital role in genre-based writing but remain underexplored in English for Specific Purposes (ESP) contexts. This study investigates how Indonesian vocational ESP students employ cohesion in written genres. Using a qualitative text analysis design, five representative texts were sampled from 20 compositions produced by second-year English Diploma students in a Genre-based Writing course. The texts were analyzed following Halliday and Hasan’s Systemic Functional Linguistics (SFL) taxonomy of cohesion, focusing on reference, substitution, ellipsis, conjunction, and lexical cohesion. Findings show that students predominantly relied on lexical cohesion (repetition, synonymy, and hyponymy) and references (anaphora, cataphora, exophora), followed by conjunctions (additive, adversative, causal, temporal). Ellipsis appeared rarely, while substitution was absent. Lexical cohesion emerged as the most frequently used device across genres, with narration and description texts showing the highest density of cohesive ties. Patterns indicate that cohesion was often achieved through repetition rather than varied lexical resources, limiting textual sophistication. These results suggest that ESP writing instruction should emphasize both the diversity and appropriateness of cohesive device use. Integrating genre-specific registers and functional linguistic awareness into teaching can better support students in producing cohesive, professional texts.