If you don't have a plan to go,you can refuse an invitation by saying,"Thank you for inviting me,but I'm sorry that I'm not free that day".If you agree first,but then you cannot be there,please be sure to tell others earlier that you're sorry for not...
you should realize that it doesn't mean you are welcome to come over to their houses at anytime. It's wise to telephone before visiting someone. Never accept an invitation unless you really plan to go. You may refuse by saying, “Thank you for inviting me, but I may not be able to...