A: Can you me?
B: Sure. (what else can B say)
A Can you help me?
C: Sorry. I can't. (Is this respones O.K? and What else C can say)
Hello everyone. My Name is Noppanat. I'm from Thailand.
It depends on what they need help with.
I'd be happy to.
It would be my pleasure.
Sure. What do you need help with?
I can try!
I'm sorry -- I can't right now.
I'm sorry -- I have a bad back. (Let's say that want you to help move a heavy item.)
I could later, but not now. Would that work?
This is a bad time. Is there another time we could do it?
I'm sorry -- I don't know anything about that.
I'm sorry -- I'm new here too and just don't know.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.