Answer:
I am sorry but I can't come to your class any more because I have to return to my country. My sister is going to get married this month. I want to go shopping with her to choose a dress. My parents are going to make a big meal for the guests and there will be a lot of work in the kitchen.
I'm sorry I must leave the English class. You are a very good teacher. Please say goodbye to the other students for me.
Thanks again,
Best wishes,
Soraya