be helpful to还是for

对某人有用是be helpful to sb.还是be helpful for sb? be helpful in be helpful to be helpful for 三者区别即怎么用 be helpful to 后面接doing 还是do 一个英语问题：是They are helpful for me还是They are helpful to me 对什么有帮助 是be help for 还是be helpful for 作文Be helpful to others Be helpful to others急! The title can be helpful for you to understang a text. 有没有be helpful（for sb） to do这个短语 be late for还是be late to Be early to.还是 be early for be eager to 还是be eager for