Abstract: With interactive voice response services, there are many different ways of asking for the same thing. In this invention the service learns the way in which a user usually asks for certain services and modifies a user specific grammar accordingly. This has the effect of increasing the accuracy of the speech recognition by reducing the number of variants which are expected. The system works well as long as the user does not suddenly start to use new words. In an improved version, the user specific grammar is checked periodically and modified if the user has introduced new words.