Abstract: The disclosure relates to an artificial intelligence (AI) system utilizing a machine learning algorithm like deep learning and applications thereof. A method of processing a language based on a trained network model includes obtaining a source sentence including a plurality of words. The method also includes determining a plurality of paraphrased sentences including paraphrased words for each of the plurality of words constituting the source sentence and levels of similarity between the plurality of paraphrased sentences and the source sentence. The method further includes obtaining a pre-set number of paraphrased sentences from among the plurality of paraphrased sentences based on the similarity levels.