Research on the role of discourse coherence in second language acquisition and teaching strategies

In the era of ever-deepening globalization, the importance of second language acquisition (SLA) has grown increasingly conspicuous. Discourse coherence, as the fundamental unit in language communication, serves not only as a crucial metric of a language user's proficiency but also as a core component for attaining effective cross-cultural communication. Nonetheless, within the current second language teaching practices, learners commonly encounter the issue of inadequate coherence in discourse understanding and production. This study conducts a comprehensive review of the mechanism of discourse coherence in SLA and the corresponding teaching strategies. By synthesizing Halliday's cohesion theory, van Dijk's global-local coherence model, and a dynamic coherence analysis framework grounded in computational linguistics, this paper puts forward staged and differentiated teaching strategies. These strategies place emphasis on striking a balance between form-focused and function-oriented training. Moreover, intelligent writing assessment tools (such as TAACO) are introduced to optimize the teaching feedback mechanism. The research findings indicate that systematic coherence-based teaching can significantly enhance learners' comprehensive language application capabilities and foster the coordinated development of their listening, speaking, reading, and writing skills.