FWU Journal of Social Sciences, Spring 2025, Vol.19, No.1, 1-11 DOI: http://doi.org/10.51709/19951272/Spring2025/1 Undergraduate English Majors' Views on ChatGPT in Academic Writing: Perceived Vocabulary and Grammar Improvement Cao Tuong Dinh FPT University Can Tho, Viet Nam This study investigates undergraduate English majors' perceptions of ChatGPT in enhancing vocabulary and grammar in academic writing. Utilizing a mixed-methods convergent design, data were collected from 31 students via pre- and post-survey questionnaires, 20 participants’ reflective journals, and semi-structured interviews with 10 volunteers. Quantitative findings revealed significant improvements in students’ perceptions of vocabulary accuracy, relevance, and depth. Thematic analysis of qualitative data identified benefits such as enriched vocabulary, improved grammatical accuracy, and increased confidence in academic writing. Challenges included overdependence, difficulty interpreting feedback, and a lack of originality in AI-generated suggestions. Students employed strategies to optimize ChatGPT use, such as asking specific questions, selectively applying feedback, and balancing AI input with personal judgment. The study highlights ChatGPT's ability to provide tailored feedback, foster confidence, and support vocabulary development while underscoring the importance of responsible use to mitigate overreliance and maintain originality. The findings underscore ChatGPT's potential to enhance academic writing skills when integrated thoughtfully into curricula. However, overuse risks shallow learning (e.g., overdependence on the tool, or difficulty in interpreting feedback), suggesting a need for instructional strategies that can promote rigorous analysis with AI tools. Future research should explore long-term impacts, comparisons with other AI tools, and strategies for ethical and effective integration of ChatGPT in higher education. Keywords: ChatGPT, vocabulary, grammar, academic writing, English majors, language learning with AI The integration of artificial intelligence (AI) into educational practices has gained significant popularity in recent years, revolutionizing traditional approaches to teaching and learning. Tools like ChatGPT, a language model developed by OpenAI, have emerged as transformative resources, particularly in language learning and academic writing. With over 100 million users reported globally within months of its release, ChatGPT has gained widespread popularity for its ability to provide instant feedback, generate personalized learning experiences, and refine written output (e.g., Liu, 2023; Shaikh et al., 2023). As higher education increasingly embraces AI technologies, understanding how tools like ChatGPT influence learning outcomes, especially in areas such as writing skills, vocabulary, and grammar, has become a pressing concern. Existing research highlights the potential of ChatGPT to enhance students' language learning experiences. For instance, Athanassopoulos et al., (2023) showed that ChatGPT has shown to significantly improve vocabulary and grammar usage among diverse populations, including students with limited language proficiency. Studies also emphasize the tool’s ability to provide real-time feedback, offer context-based vocabulary examples, and facilitate personalized exercises tailored to learners’ individual proficiency levels (Liu, 2023; Mai et al., 2024; Pellicer-Sánchez, 2015). These capabilities position ChatGPT as a valuable supplementary tool for modern language education. However, alongside these benefits, there are significant challenges. Researchers have raised concerns over the risks of over-reliance on AI tools, which may lead to shallow learning, as students accept suggestions passively without fully understanding the underlying principles (e.g., Bae & Bozkurt, 2024; Zhai et al., 2024). Ethical concerns, such as the potential for plagiarism and the reliability of AI-generated content, further underscore the importance of examining how these tools are integrated into educational contexts (Gerlich, 2025). Correspondence concerning this article should be addressed to Cao Tuong Dinh, English lecturer, English Department, FPT University Can Tho, Viet Nam, Email:TuongDC@fe.edu.vn