英語專業(yè)四級(jí)考試語法復(fù)習(xí)指導(dǎo)：It的使用

it用來充當(dāng)形式主語或形式賓語，后面的真正主語或真正賓語通常是不定式結(jié)構(gòu)、動(dòng)名詞或名詞性分句。It的這種用法叫作先行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用來充當(dāng)形式主語，后置的真正主語往往可以取代先行it的位置，出現(xiàn)在句首。
    Eg. To form a good studying habit is quite important for us
    并非所有先行it結(jié)構(gòu)都可轉(zhuǎn)化，下邊句子只能作如下轉(zhuǎn)化。
    eg.
    It seems that John is not coming after all.
    John doesn’t seem to be coming after all.
    Cleft it :
    Task
    1. 句子的基本結(jié)構(gòu)
    2 .分裂句的本質(zhì)
    3 . 分裂句的結(jié)構(gòu)
    4 .假擬分裂句
    句子結(jié)構(gòu)
    主語+謂語
    已知信息
    新信息
    末端中心
    末端重心
    Eg. I told him the news yesterday.
    分裂句的本質(zhì)
    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為引導(dǎo)詞的強(qiáng)調(diào)句型。它的結(jié)構(gòu)形式是：It +be 的一定形式+中心成分+that /who分句。通過這種結(jié)構(gòu)可以強(qiáng)調(diào)除謂語動(dòng)詞以外的大多數(shù)句子成分。說話人通過分裂句分別強(qiáng)調(diào)主語、間接賓語、直接賓語、狀語，使之成為信息中心。分裂句中的謂語可以采取復(fù)雜形式
    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 Master’s Degree.
    主語補(bǔ)語通常不作分裂句的中心成分。賓語補(bǔ)語可以這樣用。
    It is beautiful that she is.
    It is Chairman of the committee that they elected him