In a dialogue system for a motor vehicle, the dialogue system including a plurality of control keys, assigning at least one of at least on of the control keys a function from a predefined set of functions in such a manner that the function is executed upon actuation of the control key. The control key can be assigned a primary parameter, which is automatically required for executing the function, and at least one secondary parameter which relates to the method for executing the function, in such a manner that the function is executed in the manner defined by the secondary parameter upon actuation of the control key.