Disclosed are a terminal device and a method for providing additional information. A method for providing additional information of a terminal device comprises the steps of: obtaining a translation of a second language by translating an original text of a first language; extracting keywords from the translation of the second language; retrieving a text of the second language on the basis of a proportion including the extracted keywords; classifying the retrieved text on a sentence basis and determining a related sample sentence on the basis of the proportion including the extracted keywords on the sentence basis; and displaying the determined related sample sentence.