Sentence examples for if they know from inspiring English sources

So what if they know?

"If they know it, they know it".

If they know, they aren't saying.

"If they know you're afraid, you're screwed".

People talk as if they know.

I wonder if they know each other.

I don't even know if they know why they're booing".

And I don't even know if they know.

"It's even better if they know that it'll end someday".

"They will help us, if they know what is happening".

"If they know the problem, they'll get involved".