What's up? versus What is up?

Hi

Could you please tell me if both are correct?

1-What’s up? 2-What is up?

If only the first one is correct, are there some other expressions which can only be used in contraction form?

Tom

Hi Tom,
Expressions What’s up? and What is up? are the same :smiley: The difference is in contraction, as you know :smiley:

Both are right, but people would rarely ask, “What is up?” since in ordinary speech we use contractions wherever possible.