Question

It 做形式主语，后面的of,for,to在什么情况下使用？

Answer 1

句型 It's +adj. +of / for sb +to do sth .

当形容词是表示某人的‘品质“(如 brave , kind , nice )时用介逗含词 of , 指后面那孙指雀件事的性质用for , 此时不定式短语则早可放在句首作主语

如

1. It 's very nice/kind  of you to help me.

    你帮助我，你真好。

2 It 's very important for us to learn English well .

= To learn English well is very important for us .

 学好英语对我们来说很重要。

Answer 2

for主要是则型指后边那件事的性质
of主要指人
比如：It is hard for me to answer the question.hard是指后面的回答这穗睁个问题
It is kind of you to help me.kind主要是指you很好
如果还有问孙族猜题都可以问我哦.
to 一般是to do something