Doctor-patient communication is a core competency in medical education, which requires learners to adapt their communication flexibly to each clinical encounter. Although conceptual learning models exist, information about how skilled communication develops over time is scant. This study aims to unpack this process of communication learning and to identify its facilitators. We conducted a longitudinal qualitative study employing a constructivist grounded theory approach in a General Practice training setting. Over a 6-month period, we closely monitored 8 first-year and 5 third-year trainees (n = 13) by means of clinical observations, stimulated recall interviews and audio diaries. In an iterative process of data collection and analysis, we triangulated these sources across trainees (horizontal analysis) and over time (vertical analysis) to identify how themes evolved. This analysis led us to the construction of a six-stage cyclic conceptual model during which trainees: (1) have an impactful experience; (2) become aware of own communication; (3) look for alternative communication behaviours; (4) experiment with new behaviours; (5) evaluate the effectiveness; and (6) internalise the new communication behaviours. Additionally, conditions were found to support learning and reflection. Becoming a skilled communicator seems to require a continuous approach, with repeated practice and reflection to adapt and internalise communication in the clinical encounter. Consequently, we recommend that trainees be supported with tailored feedback to strengthen their communication repertoire. Ideally, they should be guided by supervisors who serve as coaches in a safe learning environment with regular, planned learning activities.