be good for 對于……來說是好事
例句：Anyway,the news seems to be good for you.
無論如何,這個消息對你來說是個好事.
be good at:擅長做…
例句：Kids really have to be good at thinking on their feet.
所以孩子們真的是必須擅長獨立思考問題.
be good to:對…好
例句：Why can't she be good to her sister?
為什么她不能對她姐姐好點?
be good with:擅長
例句：I think she can be good with Alice.
我想她可以和愛麗絲相處的融洽.
As a politician,you need to be good with words.
作為一名政治家,你必須能說會道.