Refer;v
Dear Jane,
I'm happy to hear that you are going to have a birthday party this Sunday. I'm writing this letter to thank you for your letter and thank you for inviting me to go to your party. I really want to go to this party. However, I am sorry to tell you that I cannot go to your party because I am very busy at weekend. I have to prepare for my upcoming examination at school, so it takes me a lot of time to review my lessons.
I hope that you will have an interesting party with your relatives and friends. I want to say “Happy Birthday” to you.
Best wishes,
Jenny.