(1)It is kind of you to do that. 

参考译文：你那样做真是太友善了。

句子语法结构分析如下：

形式主语：It(它）

系动词：is（是）

表语：kind（友善的，友好的）

真正主语：of you to do sth(不定式复合结构）

(备注:It is+adj. of sb to do sth=sb is +adj.to do sth结构中的形容词是用来描述人的性特特点特征的 foolish, silly, stupid, kind, )

It is so silly of you to lend him money again.

你再次借钱给他真是傻。

【1】It be +形容词（adj) of somebody to do something

=Somebody +be +adj +to do sth

（形容词为描述人的内在性格特点特征的形容词）

(表示不定式逻辑主语的性质，特点，特征)

(kind, nice, foolish, silly, stupid,rude,cruel,wise)

(clever,brave, crazy,good, careful,polite,impolite)

（considerate , right， cruel， careless）

( careless, considerate, )

It is impolite of him to say so.

=He is impolite to say so.

It is very foolish of you to lend him money again.

=You are very foolish to lend him money again.

It is kind of you to see me off at the airport.

It is wise of you to keep silent.

It is clever of him to leave that company.

=He is clever to leave that company.

It was wise of your father to make an investment in property years ago

=Your father was wise to make an investment in property years ago.

It is very foolish of you to lock the door.

=You are very foolish to lock the door.

It is very kind of you to help me.

It is very considerate of you to see me off at the airport.

It is kind of you to help me with my maths.

=You are kind to help me with my maths.

It is kind of you to see me off at the airport.

It is wise of you to keep silent.

It is very foolish of you to lend him money again.

It is very kind of you to see me off at the airport.

(2)It is easy for us to finish the work.

参考译文：完成这项工作对我们来说很容易。

句子语法结构分析如下：

形式主语：It（它）

系动词：is（是）

表语：easy（容易的）

真正主语：for us to finish the work（不定式复合结构）

(备注：It is+adj. for sb to do sth(结构中的形容词用来描述事件特点，特征，important, impossible, easy, difficult)

It is very important for us to learn English well.

学好英文对我们来说很重要。

【2】It be +形容词(adj )+for somebody to do something.

（形容词为描述事件的特点特征的形容词）

(形容词作表语常常为一些表示客观情况形容词)

（difficult, hard,  impossible, possible,)

(important, necessary ,interesting,dangerous,easy )

It's hard for me to finish the task in such a short time.

对我而言，要在如此短的时间里完成任务是困难的。

It is impossible for them to finish the work within three days.

It is dangerous for us to swim  alone in the river.

It is not easy for me to speak English.

It is easy for me to learn how to drive a car.

It is important for us to express our opinions.

It is easy for me to get up early.

It is impossible for him to arrive here within an hour.

It is very important for us to learn English well .

It will be good for her to be out in the sun.

It is not good for your eyes to read in the sun

It is difficult for us to complete the work in such a short time.

It is impossible for them to finish the project within six months.

It is not easy for Tom to learn Chinese.

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