初中英语从句知识点总结归纳

宾语从句
一． 定义：宾语从句是指在一个句子中充当宾语的句子

如：He said that he wanted to be a teacher when he grew up.

二．
宾语从句有三种类型
：
1．由从属连词that引导的宾语从句表示陈述意义，连词that常可被省略。
例如：I hope (that) they will have fun. Mary said that she felt sleepy.
Can’t you see (that) I’m a bird?
注意：（1）当主句的谓语动词是think,believe等时，宾语从句尽管要 表示否
定意义，却不用否定形式，而将think等动词变为否定形式。如：I don’t think he
will come.我认为他不会来。
（2）两个表示陈述意义的 宾语从句并列时，有时省去第一个从句的连词that，
但第二个从句的连词that一般不可以省略。 如：
He told me (that)they could not decide what to do and that they asked my advice.
2.由 从属连词if或whether引导的宾语从句表示“是否（有，能，已经??）”
等一般疑问句的含义 。
例如：I wonder whether (if) he lives here.
3.由连接代词who,whom,whose,what,which和连接副词when,wh ere,how,why
等引导的宾语从句表示“谁，谁的，什么，哪（个，些），何时，何地，怎样，
为什么”等等特殊疑问句的意义。除了连接词及被修饰的词提前以外，宾语从句
用陈述句语序。
例如：To masked who could give the message to her mother.
Do you know what he said just now? I wondered how old his brother was.
三.宾语从句的时态呼应
：
“主现则从任，主过则从过，客观真理一般
现”
1．当主句是现在时或将来时的时候，宾语从句可以用所需要的任何时态。
2．主句是过去时 ，宾语从句一般只能用过去时的某种形式；当从句叙述的是客
观事实或一般真理时，宾语从句仍然用现在 时态。
3．情态动词must一般不用于过去时，但却可以用于主句是过去时的宾语从句中。
四.宾语从句的语序

1 宾语从句的连接词后加陈述语序（主语在前，谓语在后）
如：I want to know if he can come tomorrow
2 当连接词本身又是宾语从句的主语时，后面直接加谓语动词
如：She asked me who had helped him



状语从句
英语中,修饰动词、形容词、副词等的句子成分叫状语。
状语的功用：状语说明地点、时间、 原因、目的、结果、条件、方向、程度、方

式和伴随状况等，根据状语的功能状语从句可 分为：时间状语从句、原因状语从
句、目的状语从句、结果状语从句、条件状语从句。
一．
时间状语从句：在一个句子中作时间状语的句子。
时间状语的连接词：when（当?时候） while（当?时候） as（当?时候） after
（在?以后） before（在?以前） as soon as（一?就） since（自从?到现在）
till until（直到?才） by the time（到?为止）依旧是连接词后加陈述语序。
1. when 当?的时候（一般情况下：主将从现）
I will become a teacher when I grow up
2. while 当?时
He visited a lot of places while he was traveling.
3. as 在?的同时；一边?一边?
He smiled as he stood up.
4. after 在?之后
He left the classroom after he had finished his homework the other day.
5. before 在?之前
Mr. Brown had worked in a bank for a year before he came here.
6. as soon as 一?就?(一般情况下：主将从现)
We began to work as soon as we got there.
I will write to you as soon as I get home.
7. since 自?以来 到现在
表示自过去的一个起 点时间到目前(说话时间)为止的一段持续时间。主句一般用
现在完成时，从句用一般过去时。
Mr Green has taught in that school since he came to China three years ago. (还可以用
作介词，本句从句还可以用短语：since three years ago(自三年前以来)表示。)
8 till until 直到
都可以作连词，连接时间状语，也可以作介词，与其它词构成介词短语，在句中
作状语。
They walked till until it was dark.
Xiao Ming didn’t leave home till until his father came back.
9. by the time 到?为止 (所在句子的主句应用现在或过去完成时)
By the time he gets there , his father has already gone.
By the time I got to school, the class had already began.
用法辨析：, while和as的区别
When 引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。并且
when有时表示“就在那时”。
例如： When she came in, I stopped eating. 她进来时，我在吃饭。(瞬时动
词)
When I lived in the countryside, I used to carry some water for him.
当的住在农村时，我常常为他担水。（延续性的动词）
We were about to leave when he came in. 我们就要离开，就在那时他进
来了。
While 引导的从句的谓语动作必须是延续性的，并强调主句和从句的动作同时

< br>发生（或者相对应）。并且while有时还可以表示对比。例如：
While my wife was reading the newspaper, I was watching TV.
I like playing football while you like playing basketball.我喜欢踢足球，而你喜欢打
篮球。（对比）
As 表示“一 边??一边”，as引导的动作是延续性的动作，一般用于主句和
从句动作同时发生；as也可以强调“ 一先一后。
例如： We always sing as we walk. 我们总是边走边唱。（as表示“一边??一边”）
As we was going out, it began to snow. 当我们出门时，开始下雪了。（as强调句中
两个动作紧接着先后发生，而不强调开始下雪的特定时间）
as when while都表示主、从句动作同时发生，三者差异如下：
as
表示“一边。。。一边＂的意思
when
1、还可以表示从句动词的动作在主几句动词的动作＂之前 ＂或＂之后＂发生。
2、when＝and then; at that moment (正在那个时候)
3.常用于常见搭配中
while
1、 用于时间较长时
2、 强调两个动作同时进行，并表示对比时
有时这三个连词可以互换，有时不可以。
lt was raining hard when (as) I got there.
我到那里时，正在下大雨。 ( 动作同时发生，when可换为as, 但不能换为while，
因为get是点动词.)
When I had read the article, he called me.
我看完这篇文章之后，她给我打了电话。( 从句动作发生在主句之前，注意时态
表达，只能用when )
When I got to the cinema, the film had begun.
(当)我到了电影院时，电影已 经开演了。(从句的动作发生在主句之后，只能用
when,并要注意时态)
He was about to leave, when the telephone rang.
他正要离开，忽然电话响了。( 此时不能放在句首。主句动词一般表达 “正在”
“即将”.
while, as不能代替
She thought I was talking about her daughter, while, in fact, I was talking about my
daughter.
他以为我在谈她女儿，然而，实际上在谈论我女儿。(表转折，对比，when, as
都不能代替它)
While the alien was buying a souvenir, the girl called the police.
外星人买纪念品时 ，那女孩给警察打了电话。(表示主句，从句的动作同时发生，
while后引导的状语从句的动词必须 是延续动词不能是点动词，因为它表示较长
时间)
Mother was worried because little Alice was ill, especially as (when while) father
was away.
妈妈担心，因为小爱丽丝病了，特别是他父亲不在家的时候。(此时as ,when, while

可通用)
2. 由till或until引导的时间状语从句。
till和until一般情况下两者可以互换，但是在强调句型中多用until。并且要注意
的是：如果主句中的谓语动词是瞬时动词时，必须用否定形式；如果主句中的谓
语动词是延续性动词时 ，用肯定或否定形式都可以，但表达的意思不同。例如：
I worked until he came back.我工作到他回来为止。
I didn't work until he came back.他回来我这才开始工作。
3. 由since引导的时间状语从句。
since引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。一般情
况下，从句谓语动 词用一般过去时，而主句的谓语动词用现在完成时，表述为：
现在完成时+since+一般过去时。但 在It is ＋时间＋since从句的句型中，主句多
用一般现在时。例如：
It is five months since our boss was in Beijing.我们老板离开北京有五个月了。
知识扩展
1. It is …since 从….以来多长时间了
It is five years since we met last time.
2. It is …+before?(。。。才。。。)
It was a long time before I went to sleep again.
It was an hour before(＝until) the police arrived.
二.
原因状语从句：在一个句子中作时间状语的句子。
连接词：由连词because, since, as引导, 也可由for, now that 等词引导
1.I didn’t go to school yesterday because I was ill.
2. Since everybody is here, let’s begin our meeting. 既然。。。
3. As you are in poor health, you should not stay up late. 既然。。。
4.I asked her to stay to tea, for I had something to tell her.
.用法辨析：because , since , as , for辨析
1）because语势最强，用来说明人所不知的原因，回答why提出的问 题。当原
因是显而易见的或已为人们所知，就用as或 since。
I didn’t go, because I was afraid.
Since As the weather is so bad, we have to delay our journey.
2）由because引导的从句如果放在句末，且前面有逗号，则可以用for 来代替。
但如果不是说明直接原因，而是多种情况加以推断，就只能用for。
He is absent today, because for he is ill.
He must be ill, for he is absent today.
三、
条件状语从句
连接词：if如果, unless (=if not) 如果不、除非(让步)
1. If it doesn’t rain tomorrow, we will go hiking.
2. I will go to the party unless he goes there too.
3. You will be late unless you leave immediately.
=If you don’t leave immediately, you will be late.
条件状语从句：主将从现.
He will not leave if it isn’t fine tomorrow.

四、
目的、结果状语从句
目的状语从句是指在一个句子中充当目的状语的句子。
结果状语从句是指在一个句子中充当结果状语的句子
目的状语从句连接词so that, so?that , in order that 引导。
结果状语从句连接词 so?that, such?that, so muchmany?that引导。
1. so?that 如此?以至于
He always studied so hard that he made great progress.
2. so that 以至于, 以便于
I’ll run slowly so that you can catch up with me. (目的)
I opened the window so that fresh air might come in. (目的)
3. such?that 如此?以至
It’s such nice weather that all of us want to go to the park.
4. in order that=so that 为了
We shall let you know the details soon in order that you canmay make your
arrangements.
5.比较：so和 such
其规律由so与such的不同词性决定。such 是形容词，修饰名词或名词词组，
so 是副词，只能修饰形容词或副词。 so 还可与表示数量的形容词many, few,
much, little连用，形成固定搭配。
so nice a flower such a nice flower
so many few flowers such nice flowers
so many people such a lot of people
（ so many 已成固定搭配，a lot of 虽相当于 many，但 a lot of 为名词性的，
只能用such搭配。）

难点
so+形容词或副词 so+形+a(an)+单数可数名词
so +many few+复数可数名词
so +much little+不可数名词
so?that与such?that皆可引导目的地状语从句和结果状语从句。
The boy is so young that he can’t go to school.
He is such a young boy that he can’t go to school
so +adjadv.+ that， such +n.+ that 以上两种句型都表示结果
so为副词,后接形容词，副词原型，可数名词前有many, few；不可数名词前有
much, little修饰时，应采用句型：so many (few, much, little )+n.
such为形容词, 后只能接名词。这名词既可以地可数 的，也可以是不可数的。
如果这名词是可数的,则必须在名词前加不定冠词a(an). 常见的形式是:such a
(beautiful)garden, such(nice)people.
五、
让步状语从句 让步状语从句是指在句子中作让步的状语的句子
连接词： though, although.，whether?or not
难点：though, although当“虽然”讲, 都不能和but连用. Althoughthough?but
的格式是不对的.但是他们都可以同yet (still) 连用. 所以thought (although)?

yet(still)的格式是正确的.
Wrong: Although he is rich but he is not happy.
Right : Although he is rich, yet he is not happy.
虽然他很富有, 然而他并不快乐.
Right : Although we have grown up, our parents treat us as children
Right : Although we have grown up, our parents still treat us as children.
尽管我们已经长大了,可是我们的父母仍把我们看作小孩.
although, though 辨析


although不能作并列连词，although不能作副词，放在词尾表示强调时要用even
though.
1、Even though I didn’t under a word, I kept smiling. 尽管
典型例题
1） ___she is young, she knows quite a lot.
A. When B. However C. Although D. Unless
2) ever if, even though. 即使
We’ll make a trip even though the weather is bad.
3) whether?or not 不管??都
Whether you believe it or not, it is true.
no matter 从句
结构：特殊疑问词疑问词+陈述语序或特殊疑问词+后缀ever+陈述
语序
No matter what happened, he would not mind.
Whatever happened, he would not mind.
替换：no matter what = whatever no matter who = whoever
no matter when = whenever no matter where = wherever
no matter which = whichever no matter how = however
注意：no matter 不能引导主语从句和宾语从句。
（错）No matter what you say is not useful now.
（对）Whatever you say is not useful now. 你现在说什么也没用了。
(Whatever you say是主语从句)
（错）Prisoners have to eat no matter what they’re given,
（对）Prisoners have to eat whatever they’re given. 囚犯们只能给什么吃什么
定语从句

定语是指在句子中用来修饰名词、代词的成分
定语从句是指在一个句子中作定语的句子，定语从句要放在所修饰的词后
如：I have met the doctor who is in the No.1 hospital.
定语从句的连接词：
1.连接代词：who、which、whom、whose、that
2.连接副词：when、where、why
选用连接词的关键是看先行词(定语从句所修饰的名词或代词)
一、连接代词的选用：
指人，先行词为人,在从句中做主语
Yesterday I helped an old man who lost his way.

2. whom 指人，先行词为人,在定语从句中充当宾语，常可省略。
Mr. Liu is the person (whom) you talked about on the bus.
注意：关系代词whom在口语和非正式语体中常用who代替，可省略。
指物，先行词为物,在定语从句中做主语或者宾语，做宾语时可省略
This is the pen (which) he bought yesterday.
4. that 指人时，相当 于who或者whom；指物时，相当于which。在定语从句
中做主语或者宾语，做宾语时可省略。
The number of the people thatwho come to visit the city each year rises one million.
Where is the man thatwhom I saw this morning?
5. whose 通常指人，也可指物，在定语从句中做定语,译成 的
He has a friend whose father is a doctor.
指物时，常用以下结构来代替
Do you like the book whose cover is yellow? = Do you like the book the color of
which is yellow?
介词+ 连接代词引导的定语从句连接代词在定语从句中做介词宾语时,从句常由
介词+连接代词引导
The school (thatwhich) he once studied in is very famous.
The school in which he once studied is very famous.
注意：1. 含有介词的动词短语一般不拆开使用，如：look for, look after, take care
of等
This is the watch whichthat I am looking for. (T)
This is the watch for which I am looking. (F)
2. 若介词放在连接代词前，连接代词指人时用whom，不 可用who或者that；指
物时用which，不能用that；连接代词是所有格时用whose
The man with whom you talked is my friend.
The plane in which we flew to Canada is very comfortable. (T)
3. “介词+连接代词”前可有some, any, none, both, all, neither, most, each, few等
代词或者数词
He loved his parents deeply, both of whom are very kind to him.
In the basket there are quite many apples, some of which have gone bad.
There are forty students in our class in all, most of whom are from big cities
二、连接副词的选用：
1. when指时间，在定语从句中做时间状语
I still remember the day when I first came to the school.
2. where指地点，在定语从句中做地点状语
Shanghai is the city where I was born.
3. why指原因，在定语从句中做原因状语
Please tell me the reason why you missed the plane.
注意：关系副词引导的从句可以由“介词+关系代词”引导的从句替换
The reason why for which he refused the invitation is not clear,
From the year whenin which he was going to school he began to know what he
wanted when he grew up.
Great changes have taken place in the city in I was born.
三、判断关系代词和关系副词的方法: 准确判断先行词在定语从句中的成分(主、

谓、宾、定、状)
例1. Is this the museum ___ you visited a few days ago?
A. where B. that C. on which D. the one
例2. Is this the museum ____ the exhibition was held?
A. where B. that C. on which D. the one
关系词的选择依据在从句中所做的成分，先行词在从句中做主、定、宾语时，选
择关系代词 (who, whom, that, which, whose)；
先行词在从句中做状语时，应选择关系副词 ( where 地点状语，when 时间状语，
why 原因状语)
四、介词+连接词用法说明
1）介词后面的关系词不能省略。
2）that前不能有介词。
3）某些在从句中充当时间，地点或原因状语的介词+关系词结构可以同关系副
词when ,where和why 互换
如：This is the house in which I lived two years ago. This is the house where I lived
two years ago.
Do you remember the day on which you joined our club? Do you remember the day
when you joined our club?
This is the reason why he came late. This is the reason for which he
came late.
五．限制性定语从句和非限制性定语从句
限制性定语从句举例：
china is a country which has a long history.
非限制性定语从句举例：
his mother, who loves him very much, is strict with him.
要注意区分以下几个句子的不同
his brother who is now a doctor always encourages him to go to college.
他那当医生的哥哥常鼓励他要考上大学。（他还有其他的哥哥）
his brother, who is now a doctor, always encourages him to go to college.
他的哥哥是当医生的，常鼓励他要考上大学。（他只有一个哥哥）
关系代词as和which 引导的定语从句
as和which引导非限制性定语从句，有相同之处也有不同之处。具体情况是：
1．as和which都可以在定语从句中做主语或者宾语，代表前面整个句子。
(1) he married her, aswhich was natural.
(2) he was honest, aswhich we can see.
2. as引导非限制性定语从句，可放在主句之前，或者主句之后，甚至可以切割一
个主句；
which引导的非限制性定语从句只能放在主句之后。
另外，as有“正如……，正像……”的意思
as is known to all, china is a developing country.
he is from the south, as we can see from his accent.
john, as you know, is a famous writer.
he has been to paris more than several times, which i don't believe.
注意：当主句和从句存在逻辑上的因果关系时，常用which

tom was always late for school, which made his teacher angry.
3. 当先行次受such, the same修饰时，常用as
i have never heard such a story as he tells.
he is not such a fool as he looks.
this is the same book as i lost last week.
注意：当先行次由the same修饰时，偶尔也用that引导定语从句，但是和由as 所
引导的定语从句意思不同
she wore the same dress that she wore at mary's wedding.
她穿着她在mary婚礼上穿过的一条裙子。
she wore the same dress as her young sister wore.
她穿着和她妹妹所穿的一样的裙子。
以the way为先行词的定语从句通常由in which, that引导，而且通常可以省略。
the way in which that. he answered the question was surprising.
but 有时也可以做关系词引导定语从句
there are very few but understand his idea. ( but= who don't )
定语从句只能用that的几种情况
1．当先行词是anything, everything, nothing (something 除外), few, all, none, little,
some等代词时，或者是由every, any, all, some, no, little, few, much等修饰时
Have you taken down everything that Mr. Li has said?
All that can be done has been done.
There is little that I can do for you.
注意：当先行词指人时，偶尔也可以用who
Any man thatwho has a sense of duty won’t do such a thing.
2. 当先行词被序数词修饰
The first place that they visited in London was the Big Ben.
3. 当先行词被形容词最高级修饰时
This is the best film that I have seen.
4. 当形容词被the very, the only 修饰时
This is the very good dictionary that I want to buy,
当先行词指人时，偶尔也可以用who
Wang Hua is the only person in our school who will attend the meeting？
5. 当先行词前面有who, which等疑问代词时
Who is the man that is standing there?
6. 当先行词既有人，也有动物或者物体时
Can you remember the scientist and his theory that we have learned?
同位语从句
（一）一般来说，在主从复合句 中，用作同位语的从句叫同位语从句。它通常跟
在某些名词之后，用以说明或解释该名词表示的具体内容 。可以跟同位语从句的
名词通常有：advice, decision, fact, hope, idea, information, message, news, promise,
proposal, reply, report, suggestion, word（消息），problem， question, doubt, thought
等。
They were delighted at the news that their team had won.
有时同位语从句可以不紧跟在被说明的名词后面，而被别的词隔开。 如：
The thought came to him that Tom might have returned the book.

（二）引导词
1. The news that Mr. Li will be our new English teacher is true.
2. He hasn’t made the decision whether he will go there.
3. The question who should do the work is being discussed at the meeting.
4. I have no idea what the boy is doing in the next room now.
5. We haven’t yet settled the question where we are going to spend our summer
vacation this year.
6. I have no idea how I can get to the railway station.
7. I have no idea when he will be back．
小结：① that引导同位语从句时无词义，也不充当任何成分，但通常不可以省
略，如句1；
② whether引导同位语从句时意为“是否”，通常不能用if来代替, 如句2;
③ 连接代词who, what等可以引导同位语从句，如句3， 4；
④ 连接副词where, how, when等可以引导同位语从句， 如句5，6，7。
(三) that 引导的同位语从句和定语从句
① 意义不同：同位语从句用来进一步说明前面名词的内容；而定语从句 用来修
饰、限定前面的先行词。试比较：
1. The news that our team has won the final match is encouraging.
2. The news that you told us is really encouraging.
② that的功能不同：that引导同位语从句时是一个纯连词，不充 当任何成分；而
引导定语从句时，不仅起连接作用，而且还指代先行词并在从句中充当主语、宾
语等成分。试比较：
1. Dad made a promise that he would buy me a CD player if I passed the English test.
2. Dad made a promise that excited all his children.
③ 可否省略：that在引导同位语从句时，通常不可省略。在引导定语从句时 ，
若在从句中作宾语，通常可以省略，若作主语则不可以省略。
主语从句
1 由连词that引导的主语从句: 引导词that无含义,在句中不做成分,不可以省。
That you will win the medal seems unlikely. 你想获得奖牌看起来是不可能的。
2 用连词 whether 引导的主语从句: whether有含义(是否),在句中不做成分,不可
以省。
Whether she is coming or not doesn’t matter too much.
她来不来都无关紧要。
3 用连接代词引导的主语从句(在由连接代词who, whose, whom, which, what,
whoever, whomever, whichever, whatever引导的名词性从句中，其连接代词在句
中起名词性作用，担当一定成分).
What you need is more practice.

你所需要的是更多的训练。
Whatever we do is to serve the people.
我们无论做什么都是为人民服务。
4 用连接副词when, where, why, how引导的名词性从句(其连接副词有含义,在句
中作状语。)
Where we should leave it is a problem.
注意
1. it 做形式主语,而将主语从句放在句末（尤其是当谓语较短时）。
That light travels in straight lines is known to all.
=It is known to all that light travels in straight lines.
众所周知光沿直线传播。
(当what引导的主语从句表示“…的东西”时，一般不用it作形式主语。)
错:It is a book what he wants.
对:What he wants is a book. 他想要的是本书。
固定用法和译法
（1） It is +名词+从句
It is a fact that… 事实是……
It is good news that … ……是好消息
It is a question that … ……是个问题
It is common knowledge that … ……是常识
类似的名词还有：a pity；a wonder；a good thing； no wonder； surprise等。
（2） It is +形容词+从句
It is necessary that … 有必要……
It is clear that … 很清楚……
It is likely that … 很可能……
It is important that … 重要的是……
类似的形容词还有：strange; natural; obvious; true; good; wonderful; possible;

unlikely; quite; unusual; certain; evident; worth-while; surprising; interesting;
astonishing, etc.
（3） It is +过去分词+从句
It is said that … 据说……
It is reported that … 据报道……
It has been proved that … 已证明……
It must be proved that… 必须指出……
类似的过去分词还有：known; estimated; expected; believed; thought; hoped; noted;
discussed; required; decided; suggested; demanded; made clear; found out,etc.。
当“及物动词 + 宾语”较短时，也可用这种结构。
It shocked me that Peter did not tell anybody where he was.
让我吃惊的是彼得没有告诉任何人他在哪里。
2.只用whether不用if引导主语从句.
表语从句
一. 在复合句中作表语的从句, 就叫做表语从句。表语从句一般放在系动词之后,
结构是“主语+系动词+表语从句”。
连系动词：be动词、表示持续的系动词（keep, remain, stay）、感官动词feel(摸
起来，感觉) , smell(闻起来) , sound(听起来) , taste(尝起来，吃起来) 等、表示变
化的系动词（become, grow, turn, fall, get, go,）、表终止的系动词prove, turn out(结
果是，证明是)、seem, appear（看起来···）
连系动词通常不用于被动语态和进行时态中。
He has become what he wanted to be ten years ago.
他已经成为了他10年前想成为的。
His suggestion is that we should stay calm.
他的建议是，我们应该保持冷静。
二．表语从句的引导词
1.从属连词：that whether as if as thoughasbecause
(1) that引导表语从句本身没有词义，在句中只起连接作用，不充当句子成分，
一般不能省略。
That fact is that more than seventy percent of the earth’s surface is covered by water.
连接词that一般不能省略，但当主句中含动词do的某种形式时，that可以省略。
What I want to do is (that) I can go up to him and thank him. 我想做的事是走到身
边去感谢他。
(2) whether引导表语从句表示“是否”,但不充当句子的成分。
The question is whether we can finish our work by tomorrow evening.

if 与whether均意为“是否”，但引导表语从句时，只能用whether, 不能用if。
(3)as ifthough“好像”，引导表语从句时要注意语态.
如果句中的情况与事 实不相符，从句多用虚拟语气。如果从句表示与现在事实相
反,谓语动词用一般过去式；如果从句表示与 过去事实相反时,谓语动词要用“had
+ 过去分词 ”，如果从句表示将来的可能性不大，用would (might ,could )+动词
原形.
Li Lei is now in a new jacket. He looks as if he were an American boy. (现在事实相
反)
The girl is giving us a vivid description of the moon. It seems as if she had been to
the moon many times. （与过去事实相反）
It looks as if it might rain. （与将来事实相反）
但是，如果as ifthough引导的表语从句所表示的与事实相符，从句则用陈述语气。
The clouds are gathering. It looks as if is going to rain.
(4) as引导表语从句
He looked just as he had looked ten years before.
他看起来还与十年前一样。
(5) because引导表语从句
常用结构：ThisThatIt iswas because····
That is because I don’t like Chinese.
2.连接代词：
whowhomwhosewhatwhichwhoev erwhateverwhicheverwhomever，在表语从句
中做主语、宾语、表语和定语 。
Tom is no longer what he used to be. (what做表语)
The problem is who is fit for this job. (who做主语)
This is what I want to tell you. (what做宾语)
The problem is whose work is the best. (whose做定语)
3.连接副词：whenwherehowwhy，在表语从句中做状语。
The question is how he did it. 问题是他是如何做此事的。
The question is where we can live. 问题是我们能住在哪儿。

注意
一．reason做主语或主语中包含事件的起因 时,后面的表语从句表示原因时要用
that来引导,而不用because；why引导主语从句做主 语时，表语从句用that引导，
不用because。
The reason is that he got up late.
Why he is late is that he got up late.
二. that is whybecause
(1) That is why ...是常用句型,其中why引导的从句在句中作表语,该句型通常用于
针 对前面已经说过的原因进行总结。That is the reason why ...与That is why ...是同
义的，“这就是……的原因因此……”，但是从语法结构上讲That is the reason
why ...中的why引导的是一个定语从句。
That is why she failed to pass the exam.
那就是她考试不及格的原因。(why 在表语从句中充当原因状语)
That is the reason why she failed to pass the exam.

那就是她考试不及格的原因。(why 在定语从句中充当原因状语)
(2) That is because···句型中从属连词because引导的名词性从句在此 作表语，这也
是个常用句型，意为“这就是因为……”。
That is because I got up late. 这是因为我起床迟了。
(3) “That is because...”与“That is why...”之间的不同在于“That is because...”指原因
或理由， “That is why...”则指由于各种原因所造成的后果。
I was angry. That was because he didn’t understand me.我生气是因为他不理解我。
(表语从句强调原因)
That’s why he got fired from that firm.那正是他被公司解雇的原因。(表语从句强调
结果)
三. The reason (why…for…)is was that…. ···的原因是····
The reason for his absence is that he got up late.
The reason why he is absent is that he got up late.
他缺席的原因是他起床迟了。
四. 使用虚拟语气的表语从句
在表示 建议、劝告、命令、计划含义的名词后的表语从句，谓语动词需用“should+
动词原形”表示虚拟 语气，should可省略。常见的词有：advice，suggestion，order，
req uest，proposal，plan，idea等。
My suggestion is that we （should） start early tomorrow.