This article explores the integration of Task-Based Language Teaching (TBLT) with explicit grammar instruction for teaching negation in English to B1 and B2 level learners. Drawing on Young (2003) and Leech (2006), it analyzes structural and functional aspects of negation and demonstrates a practical TBLT-based lesson design that incorporates pre-task, task, and post-task phases. The approach promotes both grammatical accuracy and communicative fluency, offering implications for EFL classrooms aiming to develop learners’ ability to use negation effectively in authentic contexts.