Over the last two decades, there has been significant debate surrounding the potential benefits, or potential harm, generated from the provision of written corrective feedback (WCF) on the writing of language learners. The majority of research in the field has been conducted within a positivist paradigm, which often adopted experimental research designs that measured language development in the form of correct output of targeted linguistic items, with the output sometimes being limited to a single writing task. Through the use of an interpretive paradigm and a socio-culturally informed theoretical framework, this case study examines language development reflected by progression within the language learners' zone of proximal development (ZPD), generated via the provision of direct WCF. Retrospective interviews provide rich qualitative data that highlight the experiences of participants as they process three different types of WCF. This case study found that WCF was not able to generate any significant shifts towards self-regulation within the participants' ZPD, and thus learning generated via WCF was, at best, minimal. The need for learners to collaborate in order to co-construct their ZPDs during both the processing of WCF and construction stage of writing tasks was identified. Pedagogical implications for language teachers are discussed.