2020届高考英语名词性从句语法复习

2020届高考英语名词性从句语法复习

高中英语语法之名词性从句

在句子中起名词作用的句子叫名词性从句(noun clauses）。名词性从句的功能相当于名词词组, 它在复合句中能担任主语、宾语、表语、同位语、介词宾语等，因此根据它在句中不同的语法功能，名词性从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。

一、引导名词性从句的连接词

引导名词性从句的连接词可分为三类：

连词：that（无任何词意）whether,if（均表示“是否”表明从句内容的不确定性）as if ,as though（均表示“好像”，“似乎”）以上在从句中均不充当任何成分

连接代词：what, whatever, who, whoever, whom,whose, whichever,whomever

连接副词：when, where, how, why,how many,how much,how often

不可省略的连词：

1. 介词后的连词

2. 引导主语从句和同位语从句的连词不可省略。

that she was chosen made us very happy. we heard the news that our team had won.

比较：whether与if 均为"是否"的意思。但在下列情况下，只可用whether：

1. whether引导主语从句并在句首

2. 引导表语从句

3. whether从句作介词宾语

4. 从句后有"or not"

whether he will come is not clear.

大部分连接词引导的主语从句都可以置于句末，用it充当形式主语。it is not important who will go. it is still unknown which team will win the match.

二. 主语从句

1、作句子主语的从句叫主语从句。主语从句通常由从属连词that，whether，if和连接代词what，who，which，whatever，whoever以及连接副词how，when，where，why等词引导。that在句中无词义，只起连接作用；连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，在从句中充当从句的成分。例如：

what he wants to tell us is not clear. 他要跟我们说什么，还不清楚。who will win the match is still unknown. 谁能赢得这场比赛还不得而知。

it is known to us how he became a writer. 我们都知道他是如何成为一名作家的。

where the english evening will be held has not yet been announced. 英语晚会将在哪里举行，还没有宣布。

有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下：

（1）it + be + 名词+ that从句（2）it + be + 形容词+ that从句（3）it + be + 动词的过去分词+ that从句（4）it + 不及物动词+ that 从句

另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should) +do”，常用的句型有：it is necessary (important, natural, strange, etc.) that …it is suggested (requested, proposed, desired, etc.) that…

2、第一部分：常规主语从句，即句子在复合句中充当一个主语

主语从句的时态：不受主句的时态影响和限制。

（1）that he finished writing the composition in such a short time surprised us all.

（2）whether we will go for an outing tomorrow remains unknown.（3）who will be our monitor hasn't been decided yet.

（4）whom we must study for is a question of great importance.

（5）what caused the accident remains unknown.

（6）whatever you did is right.

（7）who the watch belongs to was lost is unknown.

（8）what we need is time.

（9）what we need are good doctors.

小结:（1)引导主语从句连词有that,whether,who,what,whatever等（2)连词位于句首不能省略（3)主语从句大多数情况下视为三单,但也有例外,如例9

第二部分：为了防止句子头重脚轻，通常把形式主语it放在主语位置，真正主语搁置于句末

（1）it is certain that he will win the match.

（2）it is true that he has made a very important discovery in chemistry.（3）it is very likely that they will hold a meeting.

（4）it is strange that he should do that.

（5）it is important that we all should attend the meeting.

（6）it is strange that the man should have stuck to his silly ideas.

（7）it is a pity that we won't be able to go to the south to spend our summer vacation.

（8）it is still a mystery what caused the accident.

（9）it is said that he has gone to shanghai.(=he is said to have gone to shanghai)

（10）it is known to all that the gun powder was first invented by the chinese.

（11）it is suggested that the work should be done with great care.（12）it seems that he has seen the film.(=he seems to have seen the film)

（13）it happened that the two cheats were there. (=the two cheats happened to be there)

小结:（1)以that 引出的主语从句,常以形式主语it引导. it is +形容词/名词/某些动词ed + that 从句.（2) 在有些that从句中要用虚拟语气