1. An apparatus for speech recognition, comprising: a display device including a screen configured to display a plurality of domains including a general domain and at least one another domain that are selectable by a user to support recognition of a speech, the general domain being associated with a database to be referenced to support the recognition of the speech using all subject matter areas and the at least one other domain being associated with a different database than the database of the general domain to be referenced to support the recognition of the speech using a specific subject matter area; a user input device including at least one of a microphone, a touch screen, a keyboard, and a mouse configured to receive a selection of at least one domain from among the plurality of domains displayed by the user; and a communicator including an antenna configured to transmit information regarding the selection by the user of the at least one domain, wherein while the display device is displaying the plurality of domains, at least one of the plurality of domains is displayed with emphasis when information obtained in relation to a situation of the user indicates relation to the at least one of the plurality of domains to assist the user in the selection of at least one domain from among the plurality of domains, wherein the general domain and the at least one other domain are configured to have a hierarchical structure, and wherein a sentence is constructed using the at least one domain selected by the user in the selection to exemplify a level of recognizability of the speech according to the at least one domain selected by the user.