I am sure you are going to... I thought it's not possible
I thought it's not possible to say "I am sure you are going to have a great time." I thought WILL is the only answer possible. "I am sure you WILL have a great time." Now, could you tell me is it a mistake or I can really say that way (I am sure you are going to). I was told by smb that after I think, I believe, I guess and I am sure WILL is the right choice. No I am puzzled, confused, disconcerted and embarrassed.
Help me please!!