We provide an overview of research that explains what oral corrective feedback is, how it can be expressed by teachers and peers, and how it may impact the language development process. We define oral corrective feedback as a negative evidence provided in response to learner error in an oral mode. A theoretical rationale for the role of feedback is described, drawing on research from both cognitive-interactionist and sociocultural explanations of second language learning through oral communication. Examples from numerous studies are incorporated to exemplify the range of ways feedback is provided on different types of linguistic errors. Research on the relative effectiveness of different types of feedback is reviewed, as well as empirical inquiry into the role of individual and social factors that can enhance or limit the effectiveness or oral feedback, concluding that oral corrective feedback is an important factor for language learning in instructed settings. We close with recommendations for research-driven teaching practice with respect to oral corrective feedback, cautioning that teachers need to consider learner experiences and expectations of feedback, their pedagogical objectives and approach, as well as learners developmental needs, self-monitoring skills, and ability to provide feedback to one another.