maggiesensei.com/2018/06/25/how-to-use-%e3%81%a0%e3%81%a3%e3%81%a6-datte/
Detailed grammar lesson explaining six uses of the particle だって (datte), from quoting and giving reasons to emphasizing and listing examples.
GrammarParticlesJLPT N3Casual speechConversationFor childrenTutors and teachersJLPT