AmisYR : Hi, Kin! Good morning! KinnBR  : Hello, Mis! Good morning! AmisYR : What do you think if we decorate our class? KinnBR  : That’s good idea, make a wall magazine I think. AmisYR : Are you sure? KinnBR  : Yes, certainly. Our class look nice if there is a wall magazine. AmisYR : Well it is possible I suppose it but I doubt it. KinnBR  : So, what do you think? AmisYR : Why don’t we buy flowers for our class? KinnBR  : Oh, I don’t think so. It is expensive. AmisYR : You are right, but we can collect money. KinnBR  : I doubt it. I’m broke now. I don’t think can get enough money. AmisYR : Yeah, come on. I can lend you the money if you want. KinnBR  : Really? AmisYR : Of course. KinnBR  : Thank you very much. AmisYR : Don’t mention it.
Asking for :
a : may i go to concert mom?
b : of course

certainty :
a : will you come to my party?
b : i'm sure, he will come