This article assesses the current status of written CF research. It focuses specifically on the potential of written CF to facilitate L2 development, seeking answers to five of the most frequently asked umbrella questions: (1) Can written CF facilitate L2 development? (2) Are some types of written CF more effective than other types for L2 development? (3) Is written CF more effective for the development of certain linguistic forms and structures than for others? (4) Is focused or unfocused written CF more effective for L2 development? (5) Can individual and contextual factors moderate the effectiveness of written CF for L2 development? The article assesses the extent to which the reported findings reported in this body of research provide valid and consistent answers to these questions and suggests where future written CF research would do well to focus its attention. From the limitations and shortcomings of the available research, new approaches to answering some of the umbrella questions are suggested and recommendations for research that seeks answers to why written CF may or may not be effective for some learners are presented. Finally and most importantly, emphasis is given to the need to recognise the interactional effect of a wide range of individual and contextual factors (especially those that characterize the whole learner and his/her learning environment) on learner response to and use of written CF.