用作定语
▲～+n.
She is a helpful girl.她是位乐于助人的姑娘。
The teacher gave us a lot of helpful books in maths.老师给了我们许多数学上有帮助的书。
It was a helpful thing to do.这样做是有益的。
用作表语
▲S+be+～
You've been very helpful.你帮了很多忙。
She is intelligent, outgoing and helpful.她聪明、开朗、乐于助人。
The book is really helpful, don't you think?这本书真的很有用,不是吗?
I always think criticism is helpful.我总认为批评是有益的。
▲S+be+～+prep.-phrase
He is always very helpful to his mother.他对他母亲总是很有帮助。
This dictionary is very helpful to your English study.这部词典对你学习英语很有帮助。
It's helpful to us.这对我们有利。
▲It is/was+～+for〔of〕 sb+to-v
Don't throw it, it is helpful for us to repair the bike.别扔了它,它对我们修自行车有帮助。
It was helpful of you to do that.你那样做真是助人为乐之举。
用作宾语补足语
▲S+V+O+～
You may find this book helpful.你会觉得这本书很有用的。
