This explanatory mixed-method study seeks to understand the relationships between second language (L2) motivation (including the ideal L2 self and the ought-to L2 self) and students’ informal digital learning of English (IDLE) and whether such relationships are mediated by the most prominent positive emotion – enjoyment. A total of 391 Chinese university students participated in the survey, and 15 of them were interviewed later. Quantitative analysis revealed a strong positive relationship between the ideal L2 self and participants’ IDLE, which was partially mediated by foreign language enjoyment (FLE), while the hypotheses that the ought-to L2 self significantly predicted FLE and IDLE were rejected. The qualitative data added details to how a vivid and elaborate L2 vision contributed to enhanced English learning enjoyment and served as the most influential motivator for IDLE practices. Meanwhile, the external and instrumental motives could not predict Chinese university students’ enjoyment, disempowering them to invest in productive language learning practices in the informal and digitalized environment. The discussion of these findings and pedagogical implications helps to chart the path for utilizing the power of the ideal L2 self to engage Chinese university students with the extramural and digitalized language learning ecology.

This study is part of a growing wave of interest in foreign language (FL) learners’ emotions, their sources, and their effects. Previous studies have confirmed that there is a clear relationship between the emotions of foreign language enjoyment (FLE), foreign language classroom anxiety (FLCA), foreign language boredom (FLB), and foreign language performance. However, the relative importance of each emotion as a predictor of FL performance has yet to be examined, and as different teaching and learning strategies can elicit different emotions, it is difficult to determine whether FL teachers and learners should prioritize a specific emotion in course design and study. We, therefore, utilized structural equation modeling and latent dominance analysis on a sample of 502 Moroccan EFL learners in order to examine the relative importance of each emotion in predicting FL performance. We argue that it is crucial to use sophisticated statistical analyses and to collect samples from outside Western, educated, industrialized, rich, and democratic (WEIRD) countries. The latent dominance analysis revealed that FLCA had the strongest (negative) effect on English test scores. FLB had a significant—but slightly weaker—negative effect and FLE had a significant—but weaker still—positive effect. As such, it is vital that FL teachers and learners not underestimate the impact of anxiety on language learning.