If you don't be quiet, you can leave the room.

你再不安静下来就得离开房间。

youdao

If you don't be quiet you'll get kicked out of the movie theater.

如果你不安静，你会被赶出电影院的。

youdao

Don't be afraid; just be quiet!

不要害怕；只是保持安静！

youdao

Just be quiet and don't bother him any more than you can help Oh, that reminds me.

NPR: Excerpt: The Sherwood Ring

There were "untrue statements related to misbehaviour", which included: ''If you don't behave, I will call the police, " and: "If you don't quiet down and start behaving, the lady over there will be angry with you.

BBC: Most parents 'lie to their children'