1）be good with意为“灵巧的；与……相处得好”.例如：
She is good with her hands.
她手巧.
He is very good with the children.
他与这些孩子处得很好.
2）be good to意为“对……友好”.例如：
My friend was good to me when I was ill.
我生病时我的朋友对我关怀备至.
3）be good for意为 “对……有好处”.例如：
Eating more vegetables is good for your health.
多吃蔬菜对你的健康有好处.