用of 的話,adj就用來形容sb的.即形容詞是描述不定式行為者的性格、品質(zhì)的,如kind,good,nice,right,wrong,clever,careless,polite,foolish等,用of sb..故可以換成sb is adj to do
比如：it‘s nice of you to help me.=you are nice to help me.
1 It’svery kind of you to help me. 你能幫我,真好.
2 It’s clever of you to work out the maths problem. 你真聰明,解出了這道數(shù)學題.
用for是因為前面的adj是來描述do后面的sth.即形容詞僅僅是描述事物,不是對不定式行為者的品格進行評價,用for sb.,這類形容詞有difficult,easy,hard,important,dangerous,（im）possible等.如
1 It’s very dangerous for children to cross the busy street.
對孩子們來說,穿過繁忙的街道很危險.

2It’s difficult for us to finish the work. 對我們來說,完成這項工作很困難.
祝你假期愉快!加油!不明白再問!如果幫到你,請采納,謝謝!請問這道題……It's very nice ___ pictures for me.A. of you to draw B. for you to draw C. for you drawing D. of you drawingA翻譯……你給我畫畫，你真好。