Nguyen Thi , D.A. and Nguyen Thi, C.A. 2026. The Effect of Task-Based Learning on Grammar Competence and Student Engagement among Grade 11 Students: A Case Study at Phong Phu High School in Ho Chi Minh City. TTU Journal of Science. 1, 3 (Sep. 2026), 80–87. DOI:https://doi.org/10.53901/tjs.2026.v01.issue03.art09.