1. be happy with sb/sth :对某人（某事）感到高兴、满意。比如，I按摩really happy with the birthday gift you gave me yesterday.

2. be happy to do sth : 很高兴做某事 如: I am happy to help you.

3. be happy for sb: 为某人感到高兴 如: I am really happy for you.