英语专业四级语法词汇辅导:It的使用

　　it用来充当形式主语或形式宾语，后面的真正主语或真正宾语通常是不定式结构、动名词或名词性分句。It的这种用法叫作先行it。

　　eg.

　　It is quite important for us to form a good studying habit.

　　I think it important to finish the task in time.

　　it用来充当形式主语，后置的真正主语往往可以取代先行it的位置，出现在句首。

　　Eg. To form a good studying habit is quite important for us

　　并非所有先行it结构都可转化，下边句子只能作如下转化。

　　eg.

　　It seems that John is not coming after all.

　　John doesnt seem to be coming after all.

　　Cleft it :

　　Task

　　1. 句子的基本结构

　　2 .分裂句的本质

　　3 . 分裂句的结构

　　4 .假拟分裂句

　　句子结构

　　主语+谓语

　　已知信息

　　新信息

　　末端中心

　　末端重心

　　Eg. I told him the news yesterday.

　　分裂句的本质

　　Eg. I told him the news yesterday.

　　Eg. It is I that told him the news yesterday

　　分裂it

　　分裂句是以it为引导词的强调句型。它的结构形式是：It +be 的一定形式+中心成分+that /who分句。通过这种结构可以强调除谓语动词以外的大多数句子成分。说话人通过分裂句分别强调主语、间接宾语、直接宾语、状语，使之成为信息中心。分裂句中的谓语可以采取复杂形式

　　Eg.

　　It is I who am to blame.

　　It may have been at Christmas that John gave Mary a handbag.

　　It was in Shanghai that I got my Masters Degree.

　　主语补语通常不作分裂句的中心成分。宾语补语可以这样用。

　　It is beautiful that she is.

　　It is Chairman of the committee that they elected him