This special issue contains reports of research on a variety of variables that are hypothesized to have an impact on how practice affects language learning. This includes spacing of practice opportunities, the provision of feedback, training working memory, and oral versus written input. Each study is complex and clearly contextualized within the research on the multiple roles of practice for second language learning. Teachers (especially those who teach younger learners) would not find it easy to access these articles because of their complexity and sophistication. However, it is important for researchers and teacher educators to find ways to share the findings of such studies and the ideas behind them so that teachers can assess their relevance for their own instruction.