High engagement and supportive social networks appear to promote L2 sociolinguistic development. This study investigates the relationship between these two constructs and their influence on Quebec French learners' use of two informal features: "ne" deletion and first-person "on"; and two geographically conditioned features: subject doubling and "tu" questions. Twenty-one adult learners completed an interview probing their language learning experiences and a social network inventory questionnaire. Qualitative analysis of the interviews revealed three engagement levels, differentiated by motivation, efforts to initiate interaction, and perceptions of Quebec French. These were only partially related to social network factors. Quantitative linguistic analysis revealed that only subject doubling and ne deletion correlated with these predictors. Type of feature and perceptions of community linguistic norms also appear to play a role. The discussion considers pedagogical implications and directions for future research on sociolinguistic development.