How can I say no when my relatives invite me to dinner but I don’t want to go?

Say that you have an exam tomorrow and you won’t be able to study at other people’s homes. The exam is very important. If you don’t do well, it will be bad. I don’t think anyone will delay your future.

If it still doesn’t work, just give it a try. Don’t go there in the afternoon. Call them again and tell them that the classmate you are eating with is better than you at a certain moment. They will review together in the afternoon and help you by the way. They will call you again in the evening. Just say that your classmate told you a lot in the afternoon, and you have an exam tomorrow, so you want to go along with it