Flow is an intrinsic motivational state associated with full task engagement, positive affect, and enhanced performance. While research has examined how different language tasks interact with flow experiences, no study has examined learner flow experiences in a wide range of tasks using an experience sampling method to determine how universal basic task features (e.g., modality, participant structure, information distribution, and targeted skills) interact with flow. The present study aims to respond to this gap in the research. Participants were 13 teachers and 327 students from 18 intact French L2 classes in a Canadian postsecondary school. Teachers selected and implemented an average of six tasks from their personal repertoires at random moments throughout the semester. Immediately following each task, learners anonymously completed a flow experience questionnaire (N = 1408; [alpha] = 0.91), and teachers a task description questionnaire containing 17 basic task features (N = 81). Statistical analyses show that 10 of the 17 variables significantly interacted with learners' flow experiences. The results not only validate a frequently used flow measurement and establish norms for future research but also outline a framework language teachers can use to evaluate and modify practices to improve learners' subjective classroom experience.