Sentence examples for what the problem from inspiring English sources

Wonder what the problem was?

That's what the problem is".

I don't know what the problem is.

She's not sure what the problem is.

I don't see what the problem is".

It didn't say what the problem was.

"I don't know what the problem was".

Do you know what the problem was?

Do you know what the problem is?

I understand what the problem is.

"We'll see what the problem is".