这两个句型的区别!

问题描述:

这两个句型的区别!
It's...of you to...
It's...for you to...
请问怎样区分?

前者用的形容词含主观色彩,而后者则是客观色彩;前者可以将句型说成You are...to...,而后者则不能.如,It's kind of you to help me.可以说成You are kind to help me.后者则不能这样说.