3. The method of claim 2 , wherein the generating the first dialog turn information further comprises, when at least one dialog turn information corresponding to the sentence pattern information, the modal information, and the discourse marker information exist, generating the first dialog turn information with reference to a recent dialog history.
2. The method of claim 1 , wherein the generating the first dialog turn information comprises: recognizing the user speech and analyzing the user speech into morphemes; extracting sentence pattern information, modal information, and discourse marker information using the morphemes; and generating the first dialog turn information using the sentence pattern information, the modal information, and the discourse marker information.