高中考点语法系统：名词性从句
名词性从句是由if, whether, that 和各种疑问词充当连接词所引导的从句，其功同名词一样。
一．主语从句
主语从句是在复合句中充当主语的从句，通常放在主句谓语动词之前或由形式主语it代替，而本身放在句子末尾。
1.It 作形式主语和it引导强调句的比较 It 作形式主语代替主语从句，主要是为了平衡句子结构，主语从句的连接词没有变化。而it引导的强调句则是对句子某一部分进行强调，无论强调的是什么成分，都可用连词that。被强调部分指人是也可用who/whom。例如：
It is a pity that you didn’t go to see the film.
It doesn’t interest me whether you succeed or not. It is in the morning that the murder took place. It is John that broke the window. 2.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 It is common knowledge that „是常识 (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 is ＋不及物动词＋从句
It seems that„ 似乎„ It happened that„ 碰巧„ (4) it ＋过去分词＋从句
It is reported that„ 据报道„ It has been proved that„ 已证实„ 3.主语从句不可位于句首的五种情况
(1) if 引导的主语从句不可居于复合句句首。
(2) It is said , (reported) „结构中的主语从句不可提前。例如：
It is said that President Jingo will visit our school next week.(right) That President Jiang will visit our school next week is said.(wrong) (3) It happens„, It occurs„ 结构中的主语从句不可提前。例如： It occurred to him that he failed in the examination.(right) That he failed in the examination occurred to him.(wrong) (4) It doesn’t matter how/whether „结构中的主语从句不可提前。例如：
It doesn’t matter whether he is wrong or not.(right) Whether he is wrong or not doesn’t matter.(wrong) (5) 含主语从句的复合句是疑问句时，主语从句不可提前。例如： Is it likely that it will rain in the evening? (right) Is that will rain in the evening likely? (wrong) 4.What 与that 在引导主语从句时的区别
What 引导主语从句时在句时在从句中充当句子成分，如主语．宾语．表语，而that 则不然。例如：
1) What you said yesterday is right. 2) That she is still alive is a consolation.
二．宾语从句
宾语从句就是在复合句中作宾语的名词性从句，通常放在主句谓语动词（及物动词）或介词之后。
1.作动词的宾语
(1) 由that引导的宾语从句（that 通常可以省略）,例如： I heard that be joined the army. (2) 由what, whether (if) 引导的宾语从句，例如： 1) She did not know what had happened. 2) I wonder whether you can change this note for me. (3) 动词＋间接宾语＋宾语从句。例如：
She told me that she would accept my invitation. 2.作介词的宾语
例如：Our succe depends upon how well we can cooperate with one another. 3.作形容词的宾语
例如：I am afraid (that) I’ve made a mistake. That 引导的从句常跟在下列形容词后作宾语：
Anxious, aware, certain, confident, convinced, determined, glad, proud, surprised, worried, sorry, thankful, ashamed, disappointed, annoyed, pleased, hurt, satisfied, content 等。也可以将此类词后的that 从句的看作原因状语从句。
4.It 可以作为形式宾语 It 不仅可以作为形式主语，还可以作为形式宾语而真正的宾语that 从句则放在句尾，特别是在带复合宾语的句子中。 例如：
We heard it that she would get married next month.. 5.后边不能直接跟that 从句的动词
这类动词有Allow, refuse, let, like, cause, force, admire, condemn, celebrate, dislike, love, help, take, forgive等。这类词后可以用不定式或动名词作宾语，但不可以用that引导的宾语从句。例如：
I admire their winning the match.(right) I admire that they won the match.(wrong) 6.不可用that从句作直接宾语的动词
有些动词不可用于“动词＋间接宾语＋that从句“结构中，常见的有Envy, order, accuse, refuse, impre, forgive, blame, denounce, advise, congratulate等。例如： He impreed the manager as an honest man.(right) He impreed the manager that he was an honest man.(wrong) 7.否定的转移
若主句谓语动词为Think, consider, wuppose, believe, expect, fancy, gue, imagine等，其后的宾语从句若含有否定意义，一般要把否定词转移到主句谓语上，从句谓语用肯定式。例如：
I don’t think this dre fits you well.（我认为这件衣服不适合你穿。）
三．表语从句
表语从句在复合句中作表语的名词性从句，放在系动词之后，一般结构是“主语＋连系动词＋表语从句”。可以接表语从句的连系动词有be, look, remain, seem等。引导表语从句的that常可省略。另外，常用的还有the reason is that„ 和It is because 等结构。例如：
1) The question is whether we can make good preparation in such a short time.2) This is why we can’t get the support of the people 3) But the fact remains that we are behind the other claes.4) The reason he is late for school is that he mied the early bus.
四．同位语从句
同位语从句就是在复合句中作名词的同位语的名词性从句。同位语从句对于名词进一步解释，说明名词的具体内容，一般由that引导，例如：The king’s decision that the prisoner would be set free surprised all the people.
宾语从句表语从句精练：
1 Catherine said that she ___ to Guangzhou.A.has never gone B.had never gone C.has never been D.had never been 2 Linda said the moon___ round the earth.A.travelled B.has travelled C.travells D.had travelled 3I don\'t know ___ they have paed the exam.A.what B.if C.when D.where 4 I hardly understand.___ he has told me.A.that B.what C.which D.who 5.She didn\'t know___ back soon.A.whether he would be B.if would he be C.he will be D.if he will come 6.I want to know how long
A.has he been back
B．has he come back C .he has been back
D．he has come back 7..He said _________ there was going to be a meeting that evening.A.what
B.if
C.that
D.how 8.What the doctors really doubt is _____ my mother will recover from the serious disease soon.
A.when
B. how
C. whether
D. why 9.Little Tommy was reluctant to tell the schoolmaster ______ he had done the day before.
A.that
B. how
C. where
D. what 10．The reporter said that the UFO ________east to west when be saw it.
A．was travelling B．travelled C．had been traveling D．was to travel.11 It was _______ he said _________ disappointed me.
A.what „ that B.that „ that C.what „ what D.that „ what 12._____ we can\'t get seems better than
we have.
A.What; what
B.What; that C.That; that
D.That; what 13.—Do you remember ______ he came?
—Yes, I do, he came by car.
A .how
B.when C.that
D .if
14._______she couldn’t understand was ______fewer and fewer students showed interest in her leons.A.What …why
B.That …what
C .What …because
D .Why…that 15.Someone is ringing the doorbell.Go and see _______-.A .who is he
B.who he is
C.who is it
D .who it is 16.These wild flowers are so special I would do ________ I can to save
them.
A.whatever
B.that C.which
D.whichever 17 I hate ____ when people talk with their mouths full.
A it
B this
C that
D them 18 A computer can only do ____ you have instructed it to do.
A what
B that
C how
D which 19 The reason lies in ____ she works harder than the others do.
A that
B how
C it
D what 20This is all ____our teacher explained to us in cla.
A.what
B.that C.which
D.of
21.After graduation she asked to be sent to ___.
A.where she was mostly needed C.where was she needed
B.where she was most needed
D.where she needed
22.I don’t know if she ____tomorrow; if he ____, I’ll let you know.
A.comes, will come
B.will come, will come
C.will come, comes
D .comes, comes 23.The old gentleman never fails to help ____is in need of his help.
A.who
B.whoever
C.whomever
D.whom 24.Give it to ____you think can do the job well.
A.whoever
B.whomever
C.who
D.whom 25.The problem ____overworking all day long will harm his health.
A.is
B.is that
C.is which
D.that
26.The whole family were worried about Rose because no one was aware ____she had gone.
A.where that B.of where C.the place where
D.the place
答案：1-5 DCBBA 6-10 CCCDA 11-15 AAAAD16-20 AAAAB 21-25 BCBAB 26 B
