んだって

んだって is a hearsay/citation form used to report information you heard from others. It attaches to the plain form of verbs, i-adjectives, na-adjectives (with the copula だ), and nouns (with the copula だ). It signals that the speaker did not witness the information themselves, but is relaying it. It can convey a sense of surprise or new information, and is common in casual conversation.