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.
be happy 后接哪个介词
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.