Feel free to ask questions if you don't understand.

你要是不懂，可以随便提问。

《牛津词典》

You'll feel free and fresh from time to time.

你不时的会感到自由，精神饱满。

youdao

If you have any questions at all, please feel free to ask me.

如果你有什么问题，请随意问我好了。

《柯林斯英汉双解大词典》

You feel mighty free and easy and comfortable on a raft...

VOA: special.2010.03.21

The other quick thing I want to say is that I do have office hours today from 3 to 5, so feel free to stop by if you have questions about problem-set 3 that you're finishing up.

我还想说一件小事,我今天的答疑时间是三点到五点，如果你对于第三次作业还有任何疑问,请在这个时间段来找我，不必客气。

麻省理工公开课 - 化学原理课程节选

People should feel free to correct my arithmetic because it's often wrong; 90 right? Two-thirds of 90, whoops, what do I need, start again.

我要是算错了要提醒我,我总算错,90对吧,90的2/3,我说错了

耶鲁公开课 - 博弈论课程节选

Unidentified Woman: If there's anything here you want, feel free to take whatever you need there.

NPR: At Iowa Meatpacking Plant, New Workers Complain

But your organization can encourage people to feel free to express themselves and explore.

FORBES: Where Ideas Come From: Nature vs. Nurture

Nonetheless, feel free to comment if you think one of these stories stands out.

FORBES: Local Government Stupidity Contest