A speech recognition system for continuously spoken Japanese sentences SPEECH YAMANASHI is described. The system has a knowledge source, in which syntactic, semantic and vocabulary knowledge are contained. It can deal with not only simple sentences but also simple complex and compound sentences without any restriction regarding the tasks. Phoneme identification is performed in real time, and after a slight revision the speech sound is represented by a pseudo-phoneme string. In the syntactic knowledge system, all inflections of inflectional words are taken into account. The syntactic analyzer, using a syntactic state transition network, predicts following words and outputs their syntactic interpretations. The semantic knowledge system deals with the meanings of each word, in particular, it deals with case structures for verbs. The semantic knowledge is used for the prediction of following words and construction of a semantic network of input sentences. The systems with vocabularies of 254 and 538 words work for four Japanese fairy tales with 70 [86] and 45 [69] % sentence and block (enclosed by brackets) recognition scores, respectively; and if sentences are spoken phrase by phrase, sentence and phrase recognition scores of 73 and 93 % are obtained for the system with vocabulary of 1,021 words. The system has an additional version, which may be used as a speech input device of a word processor.