only if
US /ˈoʊnli ɪf/
UK /ˈəʊnli ɪf/
连词
只有在...才, 除非
used to state a condition that must be met for something else to happen
示例:
•
You can go to the party only if you finish your homework.
你只有在完成作业后才能去派对。
•
I will help you only if you promise to do your best.
我只有在你承诺尽力而为的情况下才会帮助你。