1. An electronic device comprising: a memory configured to store a Query and Answer (Q/A) set that includes a plurality of Q/As; and a processor configured to: control to acquire a speech query associated with a query uttered by a user, control to identify at least one Q/A of the plurality of Q/As based on criteria, control to generate a query list including candidate queries of the identified at least one Q/A, the candidate queries having the same or similar semantic as the acquired speech query, control to provide the query list for display, and control to perform an operation related to a candidate query selected from the query list provided for display, wherein the criteria include a time and a place of the query being uttered by the user, and at least one of user situation information, a user profile, or a past service usage pattern.