Dear Mary, Thanks for your invitation. I'd love to go to your birthday party, but I can'tŁ¬because I'm too busy. I have too many things to do (next Sunday). I have to clean my room and wash my clothes. And I have to do my schoolwork the whole morning. In the afternoon, I'm going shopping with my mother. In the evening, I have to help my mother do some housework at home. So, you see, I'm really very busy. I'm very sorry. Maybe I can go to your party next time. Thanks for asking. Happy birthday to you! I hope you have a good time! Yours