1.(some)某些；某个
Leaflets have been air dropped telling people to leave certain areas.已经空投了传单, 告诉人们离开某些区域。
You owe a certain person a sum of money.你欠某人一笔钱。
There will be certain people who'll say 'I told you so!'有人会说“我早就告诉过你了！”。
2.a certain
(before someone's name)某一(用于姓名前)
She arranged for them to be hidden in the house of a certain Father Boduen.她安排他们藏身于一个名叫鲍敦的神父的房子里。
3.a certain
(indicating a moderate amount)些许；一点儿；一些
I felt a certain bitterness.我感到一丝苦涩。