An apparatus for processing voice commands includes: a memory configured to store computer-executable instructions, and a processor configured to execute the computer-executable instructions. When executed, the instructions cause the processor to perform: receiving an utterance of a user in an input language set by the user, determining an utterance intent of the utterance by analyzing the utterance with the input language, determining a standard utterance in the input language corresponding to the utterance of the user based on the determined utterance intent, determining whether the input language and an output language are different languages, extracting a standard utterance in the output language corresponding to the determined standard utterance in the input language when the input language and the output language are different, generating an output response in the output language based on the extracted standard utterance in the output language, and outputting the output response.