How to Say "NO"

Say “NO” to people is an important class of talking. The best way to say “NO” is to offer a reason or an excuse that why you cannot do something. If someone invites you to have a dinner which you don’t like to go, you can say “I have already had an appointment on that date”, and decline the invitation. Or if someone asks you to help him or her to do something, but you can’t, you can say “I’m sorry. I can't do this right now.” Just use a sympathetic, but firm tone. You can tell them why, reply that it doesn’t fit with your schedule, and could they changes the subject. Most people will accept this as an answer. Anyway, if you want to say “NO” to somebody, try to courtesy; otherwise, others may be annoyed.