Most dialogue systems are built with a single task in mind. This makes the extension of an existing system one of the major problems in the field as large parts of the system have to be modified. Some recent work has shown that ontologies have a role on the domain knowledge representation as the knowledge collected in an ontology can be used in all the modules. This work aims to follow the footsteps of the use of ontologies in dialogue systems and take it further as the current state of the art only uses taxonomical knowledge.