A conversation manager processes spoken utterances from a user of a computer, and develops responses to the spoken utterances. The conversation manager includes a reasoning facility and a language generation module. Each response has a domain model associated with it. The domain model includes an ontology (i.e., world view for the relevant domain of the spoken utterances and responses), lexicon, and syntax definitions. The language generation module receives a response in the form of a formal belief structure from other components of the conversation manager. The reasoning facility selects a syntax template to use in generating a response output from the formal belief structure. The language generation module produces the response output based on the formal structure, the selected syntax template, and the domain model.