Though large vocabulary speech recognition systems have improved greatly in recent years, usability of these systems in practical applications is still low, due to the ever-present errors. Adding a natural interface to these systems for users to correct errors should increase acceptance. This paper describes three methods for accomplishing speech-based repair of a misrecognition. The user must respeak or spell only an errorful subsection of the original utterance. A method is described to automatically locate the respoken subpiece in up to 90% of the instances. Once the subpiece has been respoken and located, another method is described which corrects the subpiece in up to 70% of the instances. If the location is known, and the subpiece is spelled, a third method is described which uses a single spelling utterance to correct the subpiece in up to 82% of the instances. The results indicate that these methods can decrease the error rate of a CSR by two thirds using only a single short repair utterance.