Simone
be useful for sb.对…有好处; 用于形容粗旁词、名词和动词短语后，引出其后动词不定式的主语
be useful to sb.对某人有用;针对某人有用(句子的主语可以是人或物)
例句：
It is useful for somebody to do something对某人干某事是有用的
It is very useful for a person to know how to swim.对一个人昌岩来说会游泳是很有用的。
It may be useful for us to consider the data separately.把数据分别进行考虑对我们来说是有用的。
Something be useful for somebody who…对于某种类耐凳御型的人来说某物是有用的
The slow cooker is very useful for people who go out all day.慢炖锅对于整天都不
He might be useful to us.他也许对我们有用。
This information may be useful to the enemy.这条消息可能对敌人有用。
