Research has shown increasing interest in the influence of learner psychology on second language acquisition (e.g. Ellis, 2019; MacIntyre, Gregersen & Mercer, 2019). This research has demonstrated that motivation, focus, and feelings of autonomy and self-efficacy are particularly important in creating the necessary conditions for learning to occur (e.g. Dörnyei, 2009; Norton & Toohey, 2011; Piniel & Csizér, 2016; Robinson, 1995, 1997). When these factors converge, a learner can experience flow, which has been described as the “optimal experience” of engagement (Csíkszentmihályi, 1975, 1990, 2008) and has been linked to language learning success (Hong et al., 2017). Existing research has shown that student-centered, open-ended, authentic, and competitive activities tend to generate more flow than their opposites (Egbert, 2003; Zuniga & Rueb, 2018). However, these studies are scarce and have focused on a very limited quantity of immediate language-class activities, thus excluding many other possible flow experiences from consideration. To expand this line of research, this study seeks to determine what types of language-class activities generate the most flow, as well as which of the theorized psychological components of flow are most strongly associated with such experiences. Eighty-two North American undergraduate, intermediate-level (estimated CEFR B1/ACTFL intermediate mid-high) students of French, Italian, German, and Spanish completed a questionnaire about their lifetime language-learning experiences. First, the participants rated a list of activities on perceived overall flow using a Likert scale. Next, they rated the same activities on four theorized psychological components of flow (enjoyment, focused attention, control, positive challenges) also on a Likert scale (Csíkszentmihályi 1975, 1990, 2008; Egbert, 2003; Zuniga & Rueb, 2018). Finally, they answered open-ended questions about salient language-class experiences. The results of this study support the hypothesis that student-centered, open-ended, authentic, and competitive activities would generate more flow than their opposites (teacher-centered, closed-ended, inauthentic, and non-competitive). The results also revealed that enjoyment and challenges best predict flow. While competitive activities were shown to be particularly strong flow generators in the quantitative analysis, the qualitative analysis of the open-ended survey responses showed student-centered activities to be particularly associated with high-flow experiences, though usually in conjunction with other flow-generating categories. When taken together, these results suggest that, in order to create learning-favorable conditions through flow, teachers should use activities that belong to as many flow-generating categories as possible while also paying special attention to students’ perceptions of enjoyment and the challenges-skills balance. / Spanish