Written corrective feedback (CF) is a traditionally ubiquitous pedagogical practice in L2 teaching, but its contribution to L2 development has been relatively ignored. Since Truscott (1996) claimed that written CF is ineffective in L2 development and should be abandoned, a lot of researchers and practitioners have extensively investigated its role within the framework of second language acquisition and L2 writing (Ene & Kosobucki, 2016). However, no conclusive results have been obtained. Written corrective feedback for L2 development comprehensively reviews available studies on written CF from cognitive and sociocultural perspectives and outlines the directions of future research. The book consists of six chapters. Chapter 1, a general introduction of the book, begins with the aim of the book, which is to explore the impact of written CF “ on the learning of the L2” (p. 1). Then two key terms, written CF and L2 development, are defined, and the pedagogical and theoretical importance of written CF for L2 development is noted, followed by the presentation of the structure of the book. The next two chapters theoretically and empirically explore the contribution of written CF to L2 development from a cognitive perspective. Chapter 2 examines the theoretical foundations of written CF from the cognitive perspective. It first explains the differences between two types of linguistic competence (i. e., learnt and acquired) and knowledge (i. e., implicit and explicit) with reference to the essential goal of L2 learning. Supported by skill acquisition theories (e. g., adaptive control of thought model and information processing model), the claim is justified that explicit L2 knowledge can be converted to implicit, acquired knowledge through meaningful contextualized practice. As explicit forms of input, different types of written CF have different potential contributions to L2 development, in accordance with different stages of the cognitive processing of L2 information proposed by Gass’ (1997) computational framework (i. e., attention to input, comprehension of input, intake, integration and output). However, this idealized learning route toward L2 acquisition may be facilitated or interrupted by the type of written CF that learners are provided with as well as some individual factors (e. g., learners’ working memory and language learning aptitude) and contextual factors (e. g., social relationships in the classroom and instructional practices in language learning) that learners are exposed to. The extent to which these factors empirically influence the role of written CF in L2 development is the central concern of the next chapter. Chapter 3 empirically reviews cognitively informed research on the potential of written CF for L2 development. The studies reviewed are both theoretically and pedagogically driven in that they focus on whether written CF can be facilitative of L2 development as well as to what extent it works. Specifically, studies are critically reviewed in relation to the effectiveness of different types of written CF (e. g., direct error correction vs. less explicit written CF, direct error correction vs. direct error correction with more explicit written CF, and metalinguistic feedback vs. other types of written CF), the function of written CF targeting specific linguistic error types (e. g., item-based vs. rule-based forms/structures), and the efficacy of focused and unfocused written CF (i. e., CF limited to certain error categories vs. comprehensive CF). The findings of the studies mentioned above are quite contradictory due to design/execution flaws, the interaction of different individual cognitive factors (e. g., grammatical sensitivity and metalinguistic language), or individual affective and contextual factors (e. g. attitudes and beliefs about written CF and language learning backgrounds). Even though it has been empirically and theoretically corroborated that written CF has the potential to facilitate learners’ explicit L2 knowledge development, “ little attention has been given to investigations of the information processing that occurs from written CF input to modified output” (p. 66), which indicates the direction of future research. Chapters 4-5 present sociocultural tenets closely related to written CF and critically evaluate empirical studies conducted from the sociocultural stance. Chapter 4 commences with an overview of sociocultural theory (SCT), particularly on how it views development. Then two sets of interrelated constructs in SCT (i. e., Zone of Proximal Development (ZPD) and scaffolding) are introduced to explain the features of effective written CF (i. e., graduated, contingent and dialogic). Mediation and tools are also discussed to explain how written CF is delivered and processed. As an extension of SCT, activity theory (AT) combines individual and contextual variables to elaborate learners’ responses to written CF. From the sociocultural perspective, L2 development is mediated between learners and external factors, in which learners gradually internalize object-and other-regulated items, ultimately completing a language-based task independently through social interactions. Properly speaking, learners’ L2 development involves both improved accuracy in subsequent text writing and increasing self-regulation in learning. In a word, SCT and AT help improve understanding of how and why written CF may facilitate learners’ L2 development. However, development is dynamic including both progress and regression. In order to maximize its effectiveness, written CF should be attuned to learners’ evolving needs (e. g., the goals the learners intend to achieve and the context where written CF occurs). Therefore, longitudinal studies are warranted to reveal how the written CF activity changes over time. Chapter 5 evaluates studies on written CF within the framework of SCT and AT. Though considerably small both in number and in scale, but is longitudinal and interpretative, this body of research takes the form of a case study design with qualitative and quantitative data collected from authentic language learning environments. This chapter starts with the evaluation of empirical studies comparing the effectiveness of scaffolded and non-scaffolded written CF provided by teachers and peers within ZPD. Then the authors review studies on the impact of two types of mediational tools (i. e., symbolic and material) on providing and processing written CF. Within the framework of AT, written CF is viewed as an activity, involving how learners respond to teachers’ CF, what teachers’ practices are in the process of providing CF and how learners react to peers’ CF, in which individual and context-specific factors interact. This illustrates the complexities of teachers’ written CF practices and learners’ responses. The obvious defect in such studies is the lack of the analysis of learners’ new writing, just as the authors comment, “ although these studies are often longitudinal, they do not always consider the impact of written CF on L2 development” (p. 118). Chapter 6 serves as a conclusion summarizing the theoretical and empirical discussions of how and why written CF facilitates L2 development from cognitive and sociocultural perspectives, which serves as a basis for the authors to briefly depict what has been gained and what has been ignored. Finally, they propose future research. The book integrates theoretical discussions and empirical investigations on written CF under cognitive and sociocultural perspectives, which “ provide complementary insights on written CF on L2 writing” (p. 135). It not only helps us have a better understanding of the theoretical and empirical status quo of written CF research, but also gives us pedagogical suggestions on how to maximize the effectiveness of written CF in L2 teaching. It is extremely valuable for researchers and practitioners. However, no research is perfect; this volume is no exception. First of all, the distinction between explicit and implicit knowledge is too simplistic. The authors argue that the former can be converted to the latter through practice; however, how the conversion is realized is not fully explained. After all, there is no one-to-one relationship between explicit/implicit learning and explicit/implicit knowledge. Ender (2016) argues that what learners gain from explicit learning may be implicit knowledge. Furthermore, the authors acknowledge that individual factors may impact on learners’ processing of written CF. Nonetheless, some important individual factors have been overlooked in existing studies, such as personality and language learning strategies. Khanlarzadeh & Nemati (2016) also hold that there is a need to investigate the affective impact of written CF. If more individual factors were incorporated, a much deeper understanding would be obtained of the potential of written CF for L2 development. In spite of the above-mentioned limitations, the book is highly recommended for those interested in written CF. Even though providing written CF is a time-consuming job for practitioners, it is widely held that it not only improves learners’ writing skills, but also facilitates their language development. Therefore, more theoretical discussions and empirical investigations are needed on the contribution of written CF to L2 development.