As an issue of controversy, corrective or negative feedback has been a much debated and investigated topic in theory and research on second—language acquisition. This book contributes to the ongoing discussion by reporting on a classroom study which examined the effects of two corrective feedback types – recasts and clarification requests – on the acquisition of the French verb forms passé composé and imparfait. The study also looked at the role of individual differences in analytic ability, working memory and anxiety in predicting the learning gains. This research makes an original contribution by investigating the types of corrective feedback that have not previously been compared for French verb forms, by targeting high school learners, by eliciting both oral and written language production and by including tests of three factors of individual differences.