How to say..
I have a plan go somewhere with a friend, but I decided not to go because I have something else to do. Can I say I want to cancel it? But it sounds like for an appointment with an important persin for me. What should I say? Are there any other expressions?
Thanks!

Question

Answer

If your friend was a native English speaker, I would suggest phrases like, "I can't make it" or "I have to beg off."  However, if you are talking to a non-native speaker, "cancel" is fine (it isn't too formal, and isn't reserved for Business English).