10. The apparatus according to claim 9 , wherein the first output unit outputs the recognition candidate when the determining unit determines that the likelihood is larger than the threshold value.
9. The apparatus according to claim 1 , wherein the speech processing unit further calculates likelihood indicating a probability of the recognition candidate of the received input speech, and the apparatus further comprises a determining unit that determines whether the likelihood is smaller than a predetermined threshold value, wherein the generating unit generates the partial character string candidates when the determining unit determines that the likelihood is smaller than the threshold value.