In many contexts of multilingualism, language learners can initiate communication in the target language (TL), or a contact language (such as English). Patterns of use emerging from these choices vary between individuals and affect TL development. Willingness to communicate (WTC) needs to be investigated in ways that capture these variations. So far, WTC has not been studied in multilingual contexts, or using individual-level designs. This case study explores intraindividual variability in the WTC propensities of adult learners of Swedish for whom the TL and English provide viable communication options in community interaction. Carried out over a period where TL skills began to develop, the purpose was to explore the process characteristics of changes in communication-initiation propensities. A person-context dynamics perspective was employed, and analyses of time-serial data were combined with analyses of concurrently generated interview data. Results reveal how changes in WTC could be gradual and nongradual, continuous and discontinuous.