Abstract: A data processing system which suggests a valid command to a user when the user enters a question or an erroneous command. The purposes of the various commands executable by the system are stored as a plurality of intents. When the user enters a question or an erroneous command, the system looks up the intent corresponding to it and semantically compares such an intent with other intents. When another intent is found, based on the comparison, to be within a predetermined degree of similarity, the command defined by such other intent is offered as a suggestion to the user.