1.be good for意为 “对……有好处”.
Eating more vegetables is good for your health.
多吃蔬菜对你的健康有好处.
2.be good with意为“灵巧的；与……相处得好”.
=get on well with
He is very good with the children.
他与这些孩子处得很好.
3.be good /kind /nice to意为“对……好”.反义词 be harmful to,do harm to
My friend was good to me when I was ill.
我生病时我的朋友对我关怀备至.
Smoking is harmful to health.
吸烟有害健康.