A substantial body of research has investigated how form-focussed instruction contributes to language learning, but there has been very little discussion of how the knowledge provided by this research can inform language teaching. This article reviews research that addresses how grammar can best be taught in terms of four theoretically motivated instructional options: (a) structured input, (b) explicit instruction, (c) production practice, and (d) negative feedback. Given the difficulty of reaching firm conclusions based on this research, a number of possibilities for the pedagogic utilization of the information it makes available are considered, based on the distinction between teachers' practical knowledge and technical knowledge. These possibilities are (a) treating the research findings as provisional specifications to be experimented with through teaching, (b) conducting action research, and (c) conducting participatory research involving teachers and researchers working collaboratively. The need for research that investigates how teachers integrate technical knowledge into their personal pedagogical systems is also recognized.