Investigating the Interplay of Chinese English as Foreign Language Learners' Growth Mindset, Enjoyment, Adaptability, and Engagement in <scp>AI</scp> ‐Mediated Informal Digital Learning of English

ABSTRACT Background The rise of artificial intelligence (AI) has reshaped English as Foreign Language (EFL) instruction, offering new opportunities for language learning. While much of the existing research focuses on AI integration in classroom settings, limited research has explored EFL learners' autonomous engagement with AI beyond the classroom. Objectives This study aims to address this gap by examining the relationships between EFL students' engagement in AI‐mediated informal digital learning of English (AI‐IDLE), growth mindset, foreign language enjoyment (FLE), and adaptability, while also exploring the factors that influence long‐term AI‐IDLE engagement. Methods Employing an explanatory sequential mixed‐methods design, this study surveyed 357 Chinese EFL students and conducted 20 post‐survey interviews. Quantitative data were analysed using structural equation modelling with SPSS 26.0 and AMOS 26.0, while qualitative data were analysed thematically with MAXQDA 24. Results and Conclusions Quantitative results indicated that growth mindset has a significant direct effect on AI‐IDLE engagement, with adaptability serving as a robust mediator. However, FLE did not significantly mediate the relationship. Qualitative results highlighted the complex nature of long‐term AI‐IDLE engagement, shaped by both external factors and individual student characteristics.