Acceptance of AI tools and its impact on communication strategies and vocabulary adaptation: Evidence from Vietnamese English majors

The rapid development of artificial intelligence (AI) tools such as ChatGPT and Grammarly has changed the way students practice, interact with, and develop English skills, especially for English majors in Vietnam. These tools, with the capacity of providing instant feedback, suggesting alternative wording, and even simulating real conversations, have made them become valuable resources for both classroom and independent learning. Understanding how students approach and use these tools - especially in relation to communication strategies and vocabulary acquisition - is more important than ever as they are increasingly integrated into educational environments. The current study employed a mixed-methods explanatory sequential approach with English majors at a private Vietnamese university in the Mekong Delta. The study participants were 267 surveyed students, of which 12 respondents willingly participated in semi-structured interviews. Quantitative analyses showed robust correlations among PU, ATU, and AIU, and AIU significantly predicted CSC, VLS, VKS-R, and VKS-MR. The qualitative analysis found that adaptive strategies, including prompting, language switching, vocabulary filtering, repetition, and the purposeful use of new words, were connected to gains in vocabulary, learning strategies, communication abilities, and overall learning success. The study finds that AI tools significantly improve English majors' communication strategies and vocabulary development, offering practical insights for teachers, curriculum designers, and AI developers to support technology-driven, learner-focused language education.