The present invention discloses a computer-implemented method to understand queries or commands spoken by users when they use natural language utterances similar to those that people use spontaneously to communicate. More precisely, the invention discloses a method that identifies user queries or commands from the general information involved in spoken utterances directly by the speech recognition system, and not by a post-process as is conventionally used. In a phase of preparation of the system, a vocabulary of items representing data and semantic identifiers is created as well as a syntax module having valid combinations of items. When the system is in use, a user utterance is first discretized into a plurality of basic speech units which are compared to the items in the vocabulary and a combination of items is selected according to the evaluation from the syntax module in order to generate the most likely sequence of items representative of the user utterance. Finally the semantic identifiers and the data extracted from the user utterance are used to call the appropriate function that process the user request.