An arrangement is described for conducting natural language dialogs with a user on a mobile device using automatic speech recognition (ASR) and multiple different dialog applications. A user interface provides for user interaction with the dialogue applications in natural language dialogs. An ASR engine processes unknown speech inputs from the user to produce corresponding speech recognition results. A dialog concept module develops dialog concept items from the speech recognition results and stores the dialog concept items and additional dialog information in a dialog concept database. A dialog processor accesses dialog concept database information and coordinates operation of the ASR engine and the dialog applications to conduct with the user a plurality of separate parallel natural language dialogs in the dialog applications.