The serial mediating effects of learning motivation and learning engagement on the relationship between gen AI literacy and EFL perceived proficiency among vocational students.

Generative artificial intelligence (Gen AI) has emerged as a transformative technology in English language education. However, research examining the serial mediating roles of learning motivation and learning engagement in the relationship between Gen AI and vocational students' English as a Foreign Language (EFL) proficiency remains scarce. This study employed a cross-sectional survey design involving 383 vocational college students in China and utilized validated instruments measuring Gen AI literacy, learning motivation, learning engagement, and EFL perceived proficiency. The results indicated that Gen AI exerted a significant positive direct effect on EFL perceived proficiency and a strong positive effect on learning motivation. However, its direct effect on learning engagement was not statistically significant. Learning motivation significantly predicted learning engagement, whereas learning engagement was a strong predictor of EFL perceived proficiency. Furthermore, the serial mediating effect of learning motivation and learning engagement was significant, whereas their individual mediating effects were not statistically significant. These findings extend Self-Determination Theory (SDT) by demonstrating that the influence of Gen AI on EFL perceived proficiency operates primarily through a motivation-engagement pathway rather than through direct technological exposure. The results also provide practical implications for the design of engagement-oriented, AI-supported language learning environments in vocational education.