The past two decades have been prolific in publications articulating ways to move beyond teacher training and its concomitant short-term focus on methodologies and techniques for teaching lower-level courses and to establish in its place professional development embracing the long-term needs of FL graduate. However, the desire evidenced in this research to move toward professional development has not been instantiated in research-based teacher development practices for FL graduate students. This presentation explains how dynamic assessment procedures, based on sociocultural theory, can provide a tool to mediate the process of novices’ learning to teach in a way that fosters continuous development. The following questions frame the study: 1) Do novice TAs apply pedagogical knowledge from coursework on FL teaching to their own classroom practices and, if so, how? 2) How can the use of dynamic assessment assist in the development of principled practice based not merely on experiential knowledge? The audience will gain familiarity with key concepts associated with sociocultural theory and dynamic assessment. Through reading and hearing dynamic assessment procedures between teacher supervisors and novice FL teachers, they will become acquainted with principles underlying dynamic assessment as well as with concrete ways to carry it out.