I don't know, people here are asking things about I like this person & I don't know how to say it or express it.. if you were to ask me, I would say: "BE YOURSELF".
Don't be the guy/girl he/she wants you to be. If they like you too then they would accept you for you (: If anything just smile at them, say hi, & be yourself.
I know it's not much of an advice but hey it's the BEST advice ANYONE can give. Some would say just go up to her/him & confess it all.. but I would say be yourself, not someone else.
Here's a quote for you; "If you don't know where you stand with that person, then I guess it's time for you to walk, Instead of just standing there"