他们不会来，不然他们就打电话了。

They can't be coming or else they'd have called.

《牛津词典》

他们不会来告别。

They don't come and say goodbye.

youdao

他们来办事。要不然他们不会来的。

They mean business. Otherwise, they wouldn't have come here.

youdao

We're not using them to weed you out, we're using them to help you learn.

我们不会用他们来淘汰你们，而是用他们来帮助你们学习。

麻省理工公开课 - 计算机科学及编程导论课程节选

Let's see if they notice.

我们来看看他们会不会注意到。

Let's 实战 - SpeakingMax英语口语达人

They could say I won't lower my prices if you don't lower your prices, and they could put this contract in with the pricy lawyer, who's taking a day off from the divorce court, and that would secure that they wouldn't lower prices on each other.

可以协定好你不降价我就不降,然后可以找个刚处理完离婚纠纷的,著名律师来作见证人,那样他们就放心对方不会打价格战了

耶鲁公开课 - 博弈论课程节选