make sure of something …

Từ điển Oxford Advanced Learner 8th

make ˈsure (of sth/that…) idiom
1. to do sth in order to be certain that sth else happens
•Make sure (that) no one finds out about this.
• They scored another goal and made sure of victory.
• Our staff will do their best to make sure you enjoy your visit.
2. to check that sth is true or has been done
• She looked around to make sure that she was alone.
• I think the door's locked, but I'll just go and make sure.
Main entry: ↑sure_idiom