如果你的小宝宝看起来有点不愿爬或走，不用担心。

Don't worry if your baby seems a little reluctant to crawl or walk.

《柯林斯英汉双解大词典》

如果你不愿意，就不用再来了。

You needn't come again, if you don't want to.

《柯林斯英汉双解大词典》

“如果您喜欢别的东西，我很乐意帮您调换一下。”—“不用，这个很好。”

"If you'd prefer something else I'll gladly have it changed for you."—"No, this is great."

《柯林斯英汉双解大词典》

If you are a political--If you are running for office, you will tend to have volunteers and not necessarily pay people.

如果你要竞选政府职位，你往往会招一些志愿者，不用付他们钱的人。

耶鲁公开课 - 心理学导论课程节选

And we haven't talked about reactions at all yet, so you don't need to worry about the specifics of that exactly, but just that if you have this negative change in energy, you have a more stable product than you do reactant.

当然我们还没有开始讨论反应，所以你不用担心它的细节是怎么样的，你只需要知道，如果能量的变化是负值，那么你将得到一个比反应物更稳定的生成物。

麻省理工公开课 - 化学原理课程节选

And if it goes up 6 percent, well you'll go up 10 percent or more, and if it goes down, don't worry, I'm so smart your stocks won't go down.

如果股市涨了6个百分点，你可以转到10以上的百分点，如果股市跌了，你也不用担心，你选择的人会保证你买的股票不会跌。

麻省理工公开课 - 计算机科学及编程导论课程节选