It's me 和 It's I 的区别：
1、英语是It's me. 按语法是I，但是现有语言，而后有总结出来的语法，语法应让步于语言习惯。
2、It's I是语法中正确的形式，但一般口语中都说it's me. It's I的说法很正式。
3、It's me经常是单独回答别人告诉别人，“是我”，比如你打电话或者敲门的时候，对方问“谁呀？”那你就回答“It's me”。
4、关键看用在什么句子当中。 例如：It's I who am a student. 是学生的人是我。
扩展资料：
在非正式书面语或口语里，常用me代替主格形式的I；这种用法越来越普遍。例如：
A：Who's there? B：It's me.
He thought Richard to be me.
It's me who runs the school.
It isn't me that makes fun of him.
It's me造句示例如下：
1、But I'm really not sure that it's me.
但是我不确信这就是我。
2、Especially if it's me!
尤其那个人是我！
3、It's me that has grown, I think grimly.
这是我在长身体，我酷酷地想。
4、I assure you, if anyone is, it's me.
我保证，我是最守信用的人。
5、Mom, it's me, can't you see?
妈妈，那是我，你看不出来吗？
参考资料：百度百科——me
