不要以为他一定会帮助你.（需要用上Take……for granted短语）
Don't take it for granted that he is sure to help you /will help you.
take ...for granted 想当然,认为理当如此
Don't take it for granted before you do anything.
做任何事之前都不要想当然.
I take it for granted that he will succeed.
我认为他会成功是理所当然的.
I take it for granted you have read this book.
我认为你一定读过这本书.