Provided is an electronic device including a communication module, a memory, and at least one processor operatively connected to the communication module and the memory, and the memory stores instructions configured to, when executed, enable the at least one processor to: receive a first sentence via the communication module; identify a first newly coined word included in the first sentence; obtain a second sentence by identifying a first alternative word corresponding to the first newly coined word, and replacing the first newly coined word in the first sentence with the first alternative word; obtain a third sentence by correcting a grammatical error in the second sentence based on the first alternative word occurring the grammatical error when replacing the first newly coined word; and transmit the third sentence to an external device via the communication module. Other embodiments can be made.