If they cannot, we will help them.

如果他们做不到，我们将帮助他们这么做。

youdao

If they cannot be roused, immediately seek help.

如果不能被唤醒，立即寻求帮助。

youdao

Those seized are detained for 21 days if they cannot pay the fine;

被抓住后如果不能上交罚款将会被扣留21天；

youdao

She says people might have difficulty completing an activity if they cannot expect some kind of reward in return.

VOA: special.2009.09.29

I've found some people really have to come to the first and second row because they claim that if they don't hear me they cannot really go to sleep.

我发现有些人必须得在第一,二排睡觉,因为他们说如果听不到我的声音,他们就无法入睡

耶鲁公开课 - 基础物理课程节选

Often children get cabin fever if they cannot go outside to play.

VOA: special.2010.03.28

The Constitution protects people from prosecution if they cannot reasonably know that their actions are criminal.

FORBES: The Cahill Prosecution In Massachusetts: Vagueness Is Still A Problem After Skilling

And if they cannot find a job, they will find the cities prohibitively expensive.

ECONOMIST: But only for a select few

But if they cannot, Clinton should summon the will to go ahead without them.

CENTERFORSECURITYPOLICY: Stop Serbia Now