This study investigates the categories and functions of discourse markers used in narrative essays written by undergraduate EFL students, comparing usage patterns between morning and evening classes. Employing a qualitative descriptive approach, the study integrates Fraser's (1999) taxonomy to classify discourse markers into elaborative, contrastive, temporal, and inferential categories, and Schiffrin's (1987) functional framework to analyze how these markers contribute to coherence and cohesion. Data were collected from narrative essays produced by fifth-semester students and analyzed through five systematic stages, including familiarization, identification and coding, categorization, functional interpretation, and comparative analysis between classes. The findings reveal that elaborative markers were the most dominant category, accounting for 54.9% of discourse markers in the morning class and 56.4% in the evening class, indicating that students predominantly organized their narratives through additive relations rather than more complex logical connections. Inferential markers, by contrast, were the least frequently used category in both groups, suggesting limited engagement with explicit causal reasoning. Although the morning class produced substantially more discourse markers overall than the evening class, both groups exhibited remarkably similar proportional distributions across categories, indicating that discourse organization strategies were shaped more by genre demands than by classroom schedule. Overall, discourse markers contributed significantly to the coherence and cohesion of students' narrative writing, though their limited variety and underuse of inferential relations point to an underdeveloped repertoire of higher-order discourse strategies. The study underscores the importance of explicit instruction on the rhetorical functions of discourse markers to enhance EFL students' academic writing skills.