fit in with somebody

Từ điển Oxford Advanced Learner 8th

ˌfit ˈin (with sb/sth) derived
to live, work, etc. in an easy and natural way with sb/sth
• He's never done this type of work before; I'm not sure how he'll fit in with the other people.
• Where do I fit in?
•Do these plans fit in with your arrangements?
Main entry: ↑fit_derived