A device comprising: a memory storing at least one program; a user input interface configured to receive a first user input corresponding to a device usage inquiry related to a trouble occurring in the device; and at least one processor configured to provide a response operation corresponding to the device usage inquiry by executing the at least one program, the at least one program comprising instructions for: classifying the device usage inquiry by inputting the first user input to a learning model that is pre-generated; extracting operation scenario information corresponding to the first user input, based on a result of the classifying the device usage inquiry; determining a recommendation operation for trouble shooting of the device from the operation scenario information; outputting a first suggestion message for suggesting the recommendation operation; characterized in that the at least one program further comprises instructions for: receiving a second user input for executing the recommendation operation; identifying whether the trouble of the device is solved by the second user input; if the trouble of the device is not solved, the at least one program comprises also instructions for: re-classifying the device usage inquiry based on a result of the identified; re-extracting the operation scenario information based on a result of the re-classifying the device usage inquiry; determining an additional recommendation operation from the re-extracted operation scenario information; and outputting a second suggestion message for suggesting the additional recommendation operation. a memory storing at least one program; a user input interface configured to receive a first user input corresponding to a device usage inquiry related to a trouble occurring in the device; and at least one processor configured to provide a response operation corresponding to the device usage inquiry by executing the at least one program, the at least one program comprising instructions for: classifying the device usage inquiry by inputting the first user input to a learning model that is pre-generated; extracting operation scenario information corresponding to the first user input, based on a result of the classifying the device usage inquiry; determining a recommendation operation for trouble shooting of the device from the operation scenario information; outputting a first suggestion message for suggesting the recommendation operation; characterized in that the at least one program further comprises instructions for: receiving a second user input for executing the recommendation operation; identifying whether the trouble of the device is solved by the second user input; if the trouble of the device is not solved, the at least one program comprises also instructions for: re-classifying the device usage inquiry based on a result of the identified; re-extracting the operation scenario information based on a result of the re-classifying the device usage inquiry; determining an additional recommendation operation from the re-extracted operation scenario information; and outputting a second suggestion message for suggesting the additional recommendation operation. classifying the device usage inquiry by inputting the first user input to a learning model that is pre-generated; extracting operation scenario information corresponding to the first user input, based on a result of the classifying the device usage inquiry; determining a recommendation operation for trouble shooting of the device from the operation scenario information; outputting a first suggestion message for suggesting the recommendation operation; characterized in that the at least one program further comprises instructions for: receiving a second user input for executing the recommendation operation; identifying whether the trouble of the device is solved by the second user input; if the trouble of the device is not solved, the at least one program comprises also instructions for: re-classifying the device usage inquiry based on a result of the identified; re-extracting the operation scenario information based on a result of the re-classifying the device usage inquiry; determining an additional recommendation operation from the re-extracted operation scenario information; and outputting a second suggestion message for suggesting the additional recommendation operation. receiving a second user input for executing the recommendation operation; identifying whether the trouble of the device is solved by the second user input; if the trouble of the device is not solved, the at least one program comprises also instructions for: re-classifying the device usage inquiry based on a result of the identified; re-extracting the operation scenario information based on a result of the re-classifying the device usage inquiry; determining an additional recommendation operation from the re-extracted operation scenario information; and outputting a second suggestion message for suggesting the additional recommendation operation. re-extracting the operation scenario information based on a result of the re-classifying the device usage inquiry; determining an additional recommendation operation from the re-extracted operation scenario information; and outputting a second suggestion message for suggesting the additional recommendation operation.