1. A speech recognition system, comprising: a user terminal, the user terminal including a first processor configured to, transmit, to a speech recognition server, a sound signal input through an input device; receive, from the speech recognition server, a speech recognition result corresponding to the sound signal; verify the speech recognition result, the speech recognition result including a word sequence and at least one candidate word for at least one word in the word sequence; and display the word sequence, on a display device, such that the at least one word having the at least one candidate word is visually distinguishable from other words of the word sequence, wherein, in response to the at least one word being selected, the first processor is configured to display the word sequence on the display device by sequentially replacing the at least one word with a different one of the at least one candidate word such that the different ones of the at least one candidate word may be substituted into the word sequence each time the at least one word is selected without displaying a list of the at least one candidate word, the at least one candidate word is selected among at least one recognized word by selecting, from among the at least one recognized word, words that have a same starting time, if some of the at least one candidate words have the same starting time and a shorter end time, then the speech recognition server is configured to combine at least two of the recognized words to form the at least one candidate word, the at least one recognized word is recognized by the speech recognition server according to the sound signal during a recognition time period, and the recognition time period being determined based on a time when recognition of the at least one recognized word is initiated, a time when recognition of the at least one recognized word is terminated, and an allowable time value added to the time when the recognition of the at least one recognized word is terminated.