2025. USING MIND MAPS TO ENHANCE GRAMMATICAL COMPETENCE: A CASE STUDY OF SIXTH-GRADE STUDENTS IN A VIETNAMESE ENGLISH CENTER. The International Journal of Language Studies (ISSN : 3078 - 2244). 2, 2 (May 2025), 78–84. DOI:https://doi.org/10.60087/ijls.v2.n2.008.