The current study's main aim was to examine development of L2 proficiency over a short period of time by adopting an analytic framework that balances out the strengths and limitations of the existing Complexity, Accuracy, Lexis and Fluency (CALF) framework of linguistic measurement. CALF indices and discourse markers were used to analyse development of proficiency among participants on an intensive EAP course in a Study Abroad context. To investigate the differential rates of development in two different task types, gains in various aspects of proficiency were examined. The results suggest that some CALF measures adequately demonstrate L2 development over a one-month period. Discourse markers provide evidence of L2 development beyond CALF, and add a new dimension to investigating and measuring L2 development. The differences in L2 development indicated in monologic and dialogic performances imply that specific measures of analysis are more suitable to characterize development in different task types.