This study investigates the influence of first language (L1) interference on the acquisition of English grammar among Vietnamese students, with the aim of identifying common error patterns and informing more effective instructional practices. Conducted at the Eflita English Centre, the research employed a quantitative approach with questionnaires to collect learner data and perceptions. The findings indicate that structural similarities between Vietnamese and English were found to facilitate grammar learning and enhance learner confidence. However, differences between the two languages often resulted in recurrent errors in verb conjugation, tense usage, and sentence structure. Participants also reported that teaching practices, classroom environment, and cultural attitudes shaped their learning outcomes. While L1 reliance served as a support mechanism, it also contributed to consistent grammatical errors when L1 and second language (L2) structures diverged. The results highlight the dual role of L1 interference as both a facilitator and a barrier in L2 acquisition. The study concludes that targeted teaching strategies, informed by an understanding of cross-linguistic similarities and differences, can help learners overcome L1-related challenges and improve grammatical competence in English.
Tuyen et al. (Fri,) studied this question.