七、高中语法—【主语从句】讲解
高中语法主语从句讲解
如果一个句子在复合句中充当一个主语,那么这个句子就是主语从句。
①Thathe finished writing the composition in such a short time surprised
us all.
②Whatwe needare good doctors.
③Whomwe
must study foris a question of great importance.
1.主语从句的连接词
1).连接词:
that, whether
①.Thathe
will winis certain.
②.Whetherhe’ll join us in the discussionis of great importance.
2).连接代词:
who, what, which, whom , whose, whoever, whatever, whichever
①.It
is clear whois
afraid of having a change in land ownership.
②.WhatIndia needsis a law to make land ownership fairer.
3).连接副词:
when, where, why, how, how many, how much , how long, how soon, how
often
①Whenwe’ll start tomorrow will
be told soon.
②Wherewe
can buy oxen is
something we need to find out.
③Whyhe came here is
not known.
④Howwe
can protect the grain from dampneeds to be discussed.
【连接词】
1.
that—— That
the
earth moves around the sunis well known.
2.
whether——Whetherhe
will come or not
is not known yet.
3.
who ——Whowill be sent therehas not been decided.
4.
what——Whatyou
needis more practice.
5.
which—— Whichone is the bestis not clear.
6.
when, where ——Wherehe has gone is
a question.
7.
why, how——Whythere is gravityis hard to understand.
Howhe can earn a living in Britain remains
a big problem.
8.
whoever、whatever、whichever可引导主语从句。
Whoevercomes will
be welcome. Whateverhe
didwas right. Whicheverof you comes inwill receive a prize.
【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第三人称单数,但在连接代词what引导的主语从句后谓语动词的数要根据句意而定。
★为了防止句子头重脚轻，通常把形式主语it放在主语位置，真正主语后置。
1.
It is certain thathe will win the match.
2.
It is true thathe
has made a very important discovery in chemistry.
3.
It is very likely thatthey
will hold a meeting.
4.
It is strange thatthe man should have stuck to his silly ideas.
It is a pitythatwe won't be able to go to the south to spend our summer vacation.
6.
It is still a mystery whatcaused
the accident.
7.
It is said thathe has gone to Shanghai.
8.
It seemsthat he
has seen the film.
【小结】
1.以that引出的主语从句,常以形式主语it引导,结构为：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 (should
+do/should +have done)。
★用it作形式主语的结构
(1)
It is ＋
名词 ＋ 从句
It
is a fact that … 事实是…
It
is an honor that …非常荣幸
(2) It is＋ 形容词 ＋ 从句
It is natural that… 很自然…
It is strange that… 奇怪的是…
(3)
It ＋
不及物动词 ＋ 从句
It
seems that… 似乎…
It
happened that… 碰巧…
(4) It＋be+过去分词 ＋ 从句
It is reported that… 据报道…
It has been proved that… 已证实…
It is said that… 据说…
★“It”作形式主语代替主语从句的常见句型举例
①It’s
- adj. + that / wh- clause
e.g.It’s
clear / natural / certain that clause
I②It’s + p.p. + that / wh- clause
e.g.It’s said / reported / known that clause
It’s believed that he will come next week.
③It
‘s + n. + that / wh- clause
e.g.It’s
a shame / an honour / good news that clause
It’s
still a question when we’ll have our meeting.
④It + v. (n. / pron.) that /wh- clause
e.g.It made us very happy that she was chosen.
It appears that he forgot to sign the letter.
★whether与if均为“是否”，但下列情况下只用whether：
1.引导主语从句并在句首——Whetherhe
will comeis not clear.
2.引导表语从句
——The
question is whetherhe’ll come.
3.
whether从句作介词宾语——I’m
not sure about whetherwe’ll
win.
4.引导让步状语从句时
——Whetheryou
like it or not,
you’ll have to do it.
【注意事项】
1.主语从句位于句首时必须由连接词引导。
2.主语从句后置时引导词that可省略。
3.主语从句位于句首时,不能用if引导。
4.主语从句后置时,可以用if引导。
练一练
1.Whatmakes this shop different is that it offers more personal services.
2.
These wild flowers are so special I would do whateverI can to save them.
3.It
is requiredin the regulations that you should not tell people the passport of
your e-mail account.
It is pretty well understoodwhat controls
the flow of carbon dioxide in and out of the atmosphere today.
5.Whatmade the school proud wasthat more than 90% of the students had been admitted to key universities.
6.
It now appearsthat they are in need of help.
7.Whoeverknows the truth will tell you about it.
8.
It is good news thatthey
will arrive in a few days.
Use
the words below to fill in the blanks
1.
______ watch was lost is unknown.
2.
________ you did is right.
3.
_________ we will go for an outing tomorrow remains unknown.
4.
______ we need is time.
5.
______ will be our monitor hasn't been decided yet.
whether what who whose whatever
.
Whether
What
Whatever
Whose
Who
上面的空大家都填对了吗?
上面每个句子都出现了的主语从句，大家能找到吗？
1.
Whose watch was lost is unknown.
2.
Whatever you did is right.
3.
Whether we will go for an outing
tomorrow
remains unknown.
4.
What we need is time.
5.
Who will be our monitor hasn't been
decided
yet.
1.
Whose watch was lost is unknown.
2.
Whatever you did is right.
3.
Whether we will go for an outing
tomorrow
remains unknown.
4.
What we need is time.
5.
Who will be our monitor hasn't been decided yet.
2.在有些that从句中要用虚拟语气
(should
+do/should +have done)。
他出生在何地还不知道。
2.谁会赢得比赛还不知道。
3.谁来都欢迎。
4.那个人为什么被谋杀尚不知道。
Where
he was born has not been found.
Why
the person was murdered is still unknown.
Who
will win the match is still unknown.
Whoever
comes is welcome.
5.
What the teacher said today was quite right.
老师今天说的话是十分正确的。
6.
That they are badly in need of help is quite clear.
他们急需帮助，这是十分明显的。
7.
Whether they will sell the house is not yet decided.
他们是否卖掉这所房子还没有决定。
8.
Whatever was said here must be kept secret.
这里说的话都应当保密。
9.
Whoever makes mistakes must correct them.
凡犯了错误的人都必须改正。
10.
It is a pity that she has made such a mistake.
她犯了这样一个错误,真是遗憾。
11.
It is believed that at least a score of buildings were damaged or
destroyed.
据信,至少有二十座楼房遭到破坏或彻底毁掉。
That they were true sisters was clear from the facial resemblance
between them.
很明显，她们确是亲姐妹，她们的脸型很相似。
13.
Whether he’ll come here isn’t clear.
他是否会来这里还不清楚。
14.
What she did is not yet known.
她干了什么尚不清楚。
15.无论他说什么都不重要。
Whatever
he says is of no importance
16.无论谁说这话都不对。
Whoever
says that is wrong．
17.
How this happened is not clear to anyone.
这事怎样发生的，谁也不清楚。
18. Whoever comes is welcome.
不论谁来都欢迎。