This study investigated how native speakers (NS) and advanced non-native speakers (NNS) of Arabic use connectives to signal semantic relations in expository and argumentative writing. This exploratory, descriptive study analyzed 100 expository texts and 100 argumentative texts, divided equally between the NS and NNS groups. Connectives were examined in terms of (1) their functions and the type of discourse relations they signaled in the clause-, sentence-, and paragraph-initial positions, and (2) the similarities and differences between the NS and NNS groups in terms of connectives use. The study adopted Rhetorical Structure Theory (Mann & Thompson, 1988) to follow a semantic-functional approach to the analysis of discourse relations and connectives. The study identified 2,964 connectives that were not confined to the grammatical category of ?ur?f ‘particles,’ and signaled fifteen types of relations, the most frequent among which were conjunction, reason, and contrast. On average, NSs and NNSs produced comparable number of connectives per 100 words. At the clause and sentence levels, connectives organized main ideas and details within narration, description and argumentation. At the paragraph level, connectives mostly occurred in the NNS argumentative data, signaling a shift between larger text units. Salient similarities between the NSs and NNSs include the awareness of the polysemy of connectives, the diversity of connectives per text, the role of the 'zero' (i.e., no) connective to transition between main ideas within a paragraph, and the association between connectives and repetition at the morphological, word, and structural parallelism. Major differences were that, as a group, the NS participants drew connectives from a wider repertoire, produced less choppy clause and sentence transitions, and exhibited structural and pragmatic control over morphological and complex structural parallelism. The NNS group showed clear evidence of experimentation, especially when addressing the argumentative task. Findings from this study highlight the need to a reading-to-writing model in teaching connectives, encouraging TAFL teachers and curriculum designers to follow a multiliteracy approach rather than target each of the four language skills individually.