Shop Assastant : Can I help you?
Tony : Yes,please.Can I exchange this jumper? It's to big.
Shop Assastant : Sure.Have you got the receipt?
Tony : Yes.It's in the bag.
Shop Assastant : Thanks.What size do you need?
Tony : Medium.Do you have it different colour?
Shop Assastant : Let me check.Yes,it comes in wide range of colours.Have a look.
Tony : I'd like white,please
Shop Assastant : Threre you go.White,in medium.
Tony : Thanks.