10.2 从属连词
从属连词用来引导从句。常见的从属连词有：
(1)引导时间状语从句的after, before, when, while, as, until, till, since, as soon as等。
(2)引导条件状语从句的if, unless等。
(3)引导原因状语从句的because, as, since等。
(4)引导目的状语从句的so that, in order that等。
(5)引导让步状语从句的though, although, even if等。
(6)引导结果状语从句的so that, so„that, such„that等。 such„that等。
(7)引导比较状语从句的than, as„as等。
(8)引导名词从句的that, if , whether等。
10.2.1 引导时间状语的连词：when, while, as, after, before, since, till/until, as soon as, once 一旦
注：引导时间状语从句的连词还有：the minute, the moment, whenever, instantly, immediately, no sooner„than, hardly„when„, scarcely„when. each(every, next, the first)time等。 hardly„when„, scarcely„when. each(every, next, the first)time等。
I was about to go out when he came in.
我正要出去时他进来了。
I was walking on the street when it suddenly began to rain.
我正在街上走的时候突然下起雨来。
We should strike while the iron is hot.
我们应该趁热打铁。
It will be five years before we meet again.
5年后我们才能再见面。
As soon as he got there, he wrote to me.
他一到那儿，就给我写信。
Once he said that, I knew he was lying.
他一那样说，我就知道他在撒谎。
No sooner had he sat down than the bell rang.
他刚一坐下铃就响了。
I finished my homework before I went home.
在我回家之前我完成了我的家庭作业。
He arrived after the class started.
when，while，as的区别：
l）when引导的状语从句中谓语动词的动作与主句中谓语动词的动作可同时发生，也可先于或后于发生；从句中的动词既可用延续性动词，也可用短暂性动词。
2）while引导的状语从句中的动词与主句中的动词动作同时发生，从句中一般使用延续性动词,句子多用进行时态。
He was doing his homework when I came in.
当我进来时， 他正在做家庭作业。
I came in when /while he was doing his homework.
当他做家庭作业时，我走了进来。
When /while I was in the town, I saw him twice.
当我在镇上时， 见过他两次。
3）as引导的时间状语从句中的动作与主句中的动作同时发生。as强调“一边„一边„”。
He hurried to school， looking behind as he went.
他匆忙的赶往学校，一边走一边回头看。
另外，当when，while，after, before引导的时间状语从句中的主语与主句的主语一致时，这四个词后可直接接动词-ing形式。如：
After spending the weekend in the capital, we took a taxi to the airport.airport.
在首都度过周末以后，我们就乘出租车到了机场。
Waste water from a number of factories is now “cleaned”before flowing back into rivers. cleaned”before flowing back into rivers.
从许多工厂流出来的废水在流入河流以前就被“净化”了。
10.2.2 引导原因状语的连词：because，as，since，now that, seeing that因为，由于
He didn’t come to school yesterday because he was ill.
昨天他没来学校是因为他病了。
As all the seats were full, he stood up.
由于所有座位上都有人，他就站着。
Since you have to stay home， why don’t you do some shopping．
既然你不得不呆在家里，为什么不购物呢？
Seeing that it’s raining, you’d better stay indoors.
既然天在下雨，你最好呆在家里。。。
注意：because, so这两个连词同样不能用在同一个句子中。
我们不能说“Because John was ill, so I took him to the doctor.”
这个句子应改为Because John was ill, I took him to the doctor.
或John was ill, so I took him to the doctor.
because, since, as与for的区别：
l）because引导原因状语从句，表示直接而明确的原因或理由，它的语气最强，它引导的原因状语从句可放在主句之前，也可放在主句之后。
2）since和as引导的从句强调结果，不强调原因，它们引导的从句一般放在句首。since比as语气强，表示自然的因果关系，意为“既然”。as表示的原因语气最弱，常用于口语中，讲话人认为某种理由很明显或对方很熟悉，不需要突出。
3）for为并列连词，虽常译为“因为”，语气最弱。但它并不说明一种原因，通常只表示一种补充或附带的解释或说明，或表示一种推理。所以，for引导的句子不能放于句首。
It must have rained last night, for the ground is wet.
昨晚一定下雨了，地面是湿的。
4）由于because引导的原因状语从句表示一种直接的原因或理由，所以能够回答why的提问。since, as, for都不能。
5）只有because引导的原因状语从句可以放在强调句型中，成为强调的对象。since，as，for引导的从句不能。
It is because he is ill that he is absent from school.school.
正式因为他生病了，所以他没有来学校。
10.2.3 引导条件状语的连词：if, unless, as/so long as
We will stay indoors if it rains tomorrow.
如果明天下雨我们就呆在家里。
They will stand by you even if you don’t succeed．
即使你不会成功，他们也会站在你一边的。
Don’t touch anything unless your teacher tells you to.to.
老师不让就别动任何东西。 I am happy as long as you are happy.
只要你高兴，我就高兴。
注：if条件句中有些词如 it is，he is等可以省略；省略后if后可直接接形容词，过去分词或副词。
If true, this will cause us a lot of trouble.
如果属实，这会给我们带来许多麻烦。
An illness can result in total blindness if left untreated.untreated.
有种病如不治疗会引起失明。
Are you busy this afternoon? If not, I wish you would stay with me for a while.while.
下午忙吗？如果不忙，我希望你能和我呆一会儿。
if, whether区别
if和whether都可作“是否”讲，在引导宾与从句是一般可互换。例如：
I wonder whether (if) you still study in that school.
I don’t know whether (if) he likes that film. 在下列情况下，只能用whether,不能用if：
1) 引导主语从句时。例如：
Whether he will come to the party is unknown.
2) 引导表语从句时。例如：
The question is whether I can pass the exam.
3) 在不定式前。例如：
I haven’t made up my mind whether to go there or not.
10.2.4 引导地点状语的连词： where, wherever, everywhere, anywhere
They went wherever they could find jobs.
他们去任何能找到工作的地方。
Where there is a will, there is a way.
有志者，事竟成。
10.2.5 引导目的状语的连词：（so）that，in order that，for fear that唯恐；以免，in case（that）以防，免得
I got up early in the morning so that I could catch the first bus.bus.
我早晨早早起床以便能赶上第一班公共汽车。
Here is a pound in case you should need it.
这里有一英镑以防你要用。
10.2.6 引导结果状语的连词：（so）that，so„that, such„that, but（that）
My pen fell under my desk, so that I couldn’t see it.it.it.
我的钢笔掉到了桌子下面，所以看不到了。
George often told stories that weren‘t true, so that no one believed him when he told about a tiger in the school yard.
乔治经常讲一些不真实的故事，结果当他说校园里有一只老虎时，没人相信他。
so that引导结果状语从句时，so that前一般有逗号。
| so+形容词或副词+that。 |
| so+形容词+a/an+可数名词单数+that。 |
| So+many/few+可数名词复数+that |
| So+much/little+不可数名词+that |
His English in one of this articles was so good that Engels wrote him a letter and praised him for it. letter and praised him for it.
他一篇文章中的英语如此之好以至于恩格斯写信赞扬他。
It was so lovely a day that we went out.
天气那么好，我们就出去了。
Such that 引导结果状语从句 引导结果状语从句
| such+ a (an)+形容词+可数名词单数+that从句 |
| such+形容词+ 不可数名词 /可数名词复数+that从句 |
It was such a hot day that nobody wanted to do anythinganything
天气这么热，没有人想干活。
He made such rapid progress that before long he began to write articles in English for an American newspaper.newspaper.
他取得了如此快的进步，不久他就开始用英语为一份美国报纸写文章。
4）such与one，no等词一起修饰名词时，这些词放在such前面。即 one, no, any, all, many, some, several„+such+单数或复数可数名词
Once in the examination hall all such trivialities were forgotten.
一进考场，所有这样的小事全都忘了。
There is a grave necessity for more such activities.activities.
多进行这样的活动是很必要的。
10.2.7 引导比较状语的连词：than，as„as，not as „as, the 比较极„the 比较极 7）引导比较状语的连词：than，as„as，not as „as, the 比较极„the 比较极
He can speak English as well as a foreigner.
他讲英语和外国人一样好。。
The longer you stay with him, the better you will know him.
和他在一起呆的时间越长，你就会越了解他。
10.2.8 引导让步状语的连词： though，although, as, even though, even if, whether„or„however, whatever, whoever, no matter how/ what/ which„ 8）引导让步状语的连词： though，although, as, even though, even if, whether„or„however, whatever, whoever, no matter how/ what/ which„
Though I prefer a colour TV, I have decided to buy a black and white one this time. I prefer a colour TV, I have decided to buy a black and white one this time.
虽然我喜欢彩电，但我决定这次买一台黑白的。
Proud as these nobles are, he is afraid to see me.me.
尽管这些贵族很自负，但他还是很怕见我。
They will play the game even if it rains hard tomorrow．
那怕明天下大雨，他们也会进行比赛的。
No matter what happened, he would not mind. =whatever happened, he would not
Mind.
不管发生什么， 他都不会介意。
though=although(语气强) even though=even if
though或although和but不能同时在句中出现；但和yet可同时出现在一个句子中。
10.2.9 引导方式状语从句的连词，as正如, as if/though似乎, 好像 引导方式状语从句的连词，as正如, as if/though似乎, 好像
He speaks English as if he were an English-man.
他讲起英语来就像是英国人似的。
Use a book as a bee does a flower.
像蜜蜂利用花一样去利用书籍吧。
