But if english isn't your native language, you might think, I don't know the ceiling fan, you know what?

When people ask this question, they're not literally asking what's up and they're not even asking how we use it idiomatic lee, which is to say what's going on with you.

It's just another way to say hi there, literally just saying hi when they say what's up?

So how do you respond to the question?

What's up?

The most common easiest answer?

The one that's most expected is nothing or not much, what's up with you?

So say nothing or not much and then return the question.

That is generally how we respond to the screening.