The concept of learner engagement has traditionally been examined in the field of education and it has been found to be associated with positive educational outcomes. While several studies in second language acquisition have looked at learner engagement with corrective feedback, there is a dearth of research investigating its relevance to successful language learners and effective language learning. Through a narrative inquiry, this study reports an individual language learner's engagement in the acquisition of a second language (L2) -- Cantonese. The learner went through three different stages in his learning process, namely the period of silence, the period of early production and experimentation, and the period of continued development and communicative competence. At each stage of learning process, three major types of engagement were observed: behavioural, affective, and cognitive. Individual and contextual factors that influenced learner engagement with language learning were also identified. The findings of this study suggest that the integration of the three types of learner engagement with L2 learning goals, tasks, and context is conducive to effective language learning. The study concludes with some pedagogical implications for both L2 teachers and learners.