1. A guide sentence generating method implemented by one or more processors, the guide sentence generating method comprising: receiving speech data corresponding to user speech from an electronic apparatus; analyzing the speech data, determining a category of the speech data from among a plurality of categories, and storing the analyzed speech data in the determined category; determining a usage frequency and a global popularity of each of the plurality of categories, wherein the usage frequency comprises a count of speech data of an individual user and the global popularity comprises a count of speech data of a plurality of users; selecting a category from among the plurality of categories based on the usage frequency and the global popularity; generating a guide sentence corresponding to the selected category; transmitting the guide sentence to the electronic apparatus; and providing the guide sentence to the user in at least one of visual and audio form, so that the user may command the electronic apparatus using the guide sentence.