1. A computer-implemented method in a dialog system, comprising: defining a set of one or more grammar rules defined for various objects within an application executed by the dialog system; labeling each grammar rule of the set of grammar rules with semantic or syntactic characteristics by annotating each grammar rule with a specific item of information regarding each element of the respective grammar rule to produce labeled grammar rules; generating labeled sentences from the set of labeled grammar rules to preclude the need to label sentences after they are generated; and using the labeled sentences to train one or more statistical models to be used by a spoken language unit of the dialog system.