1. A speech recognition method for resolving unrecognized sound groups in a partially recognized speech using concept to keywords mappings and sentence types, each sentence type having a plurality of associated grammar rules, the grammar rules being expressed in concepts, said method comprising the steps of: parsing the partially recognized speech using a natural language processor into a pre-determined sentence type and an associated ordered list of recognized words and place holders corresponding to the unrecognized sound groups; selecting a list of grammar rules associated with the sentence type from a plurality of grammar rules, each grammar rule of said list having a plurality of constituent concepts, each of said constituent concepts corresponding to one of the recognized words and the unrecognized sound groups; for each said unrecognized sound group, merging said corresponding constituent concepts in all said selected grammar rules into a list of concepts; expanding said list of merged concepts using the concept to keywords mappings to produce a list of candidate words wherein each of the merged concepts are expandable to a plurality of words conceptually related to each of the expanded concepts and wherein the plurality of words are the list of candidate words; and providing the list of candidate words to a speech recognition engine to enable the speech recognition engine to use the list of candidate words to resolve each said unrecognized sound groups in the partially recognized speech corresponding to the place holders.