我怕对方碍于面子不好意思直接指出我的错误，怎么说能让对方打消这样的顾虑？
追答老外都是很直的人，不会碍面子的。你可以说：
I don't think that my essay is good enough.
I really need help to get it better. Could you
please edit it ? I really appreciate.
就是我写了一篇essay，想让英语为母语的朋友帮我纠正一些语法错误，还有一些逻辑结构之类的问题，怎么表达会比较礼貌得体？还有我怕人家会碍于面子不好意思指出我的错误，所以想顺便表达让对方不必有这方面的顾虑。
追答Can you do me a favor? I have written an essay, I want you to see if there is any grammar mistake or structure problem I can correct. I will be pleased if you point out my problem.