The current study investigated advanced L2 learners' linguistic development before, during, and after a nine-month stay abroad, the extent to which contextual changes (home-abroad-home) influenced the nature and magnitude of development, and the ways in which relationships among different linguistic elements changed over time. Participants were 56 university learners majoring in French (n = 29) and Spanish (n = 27), who spent an academic year abroad in the middle of a four-year BA degree programme. Oral data were collected six times over 21 months to trace development and change in complexity, accuracy, fluency, and lexis. Results showed ongoing improvements over time on most measures, including accuracy. Correlations indicated long-term relationships between fluency and vocabulary only and that accuracy-complexity relationships emerged in instructed home contexts only. These findings suggest that the affordances of home and abroad contexts can shape learners' linguistic development and use differently. The role of pre-departure linguistic ability is discussed as critical to understanding the nature and extent of L2 linguistic development in study abroad.