then again

Từ điển Oxford Advanced Learner 8th

but ˈthen | then aˈgain | but then aˈgain idiom
(informal)used to introduce additional information or information that contrasts with sth that has just been said
•She was early, but then again, she always is.
•‘So you might accept their offer?’ ‘Yes, then again I might not.’
Main entry: ↑then_idiom