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2008-08-10 21:52:26
5)、表达“条件”的连接词
条件状语从句是表示主句动作发生的前提或条件的从句。引导条件状语从句的连词有if, unless,as/so long as,on condition that,in case,suppose, supposing等。
条件状语从句中的谓语动词一般要用现在时或过去时代替一般将来时或过去将来时。
if 引导的条件句有真实和非真实条件句两种。非真实条件句将在虚拟语态中阐述。
(1)、if表示正面条件，意为“如果”。
If you ask him, he will help you.如果你向他请求，他会帮助你。
Difficulties are nothing if we are not afraid of them.
如果我们不怕困难，困难就算不了什么了。
If you are willing to learn，I could reach you Chinese.
You’ll miss the bus if you don’t hurry up.
If you touch the wrong button，the machine will break down.
提示：有时表示条件的 if之后可能用will或would，但那不是将来时态, 而是表示意愿或委婉的请求。
If you will sit down for a few moments, I’ll tell the manager you’re here.
请稍坐, 我这就通知经理说您来了
If you will go with me, I’ll wait for you. 如果你愿意等我，我们就帮你做这事儿。
(2)、unless= if not,表示反面条件，意思是“如果不”、“除非”。
They will go tomorrow unless it rains.
(= They will go tomorrow if it doesn't rain.)
除非明天下雨，否则他们会去的。
I won't let you in unless you show me your pass.
(= I won't let you in if you don't show me your pass.)
如果你不出示通行证，我就不让你进来。
Let's go out for a walk unless you are too tired.
= If you are not too tied, let's go out for a walk.
注意：if...not和unless通常是可以换用的。但在下列情况下，两者是有区别的：
A、unless多引导真实条件句，if...not可以引导真实条件句或非真实条件句。
He won't be able to pass the final exams unless he works hard.
除非他努力，否则就通过不了期末考试。
He won't be able to pass the final exams if he doesn't work hard.
如果他不努力，就通过不了期末考试。
B、如果主句描述的是情感或情绪活动方面的面容，if...not结构不能换成unless。
I'll be quite a glad if she doesn't come this evening. 她今晚如果不来我很高兴。
C、unless引导的状语从句可用否定结构。
Don't ask me to explain again unless you really don't understand.
不要再叫我解释了，除非你真的不懂。
D、unless能作为介词使用，相当于except。
Nothing will come out of it unless disaster.这种事除了引起灾祸之外不会有什么结果。
(3)、as/so long as, on condition that都表示“只要，条件是……”。
As/So long as we don't lose heart, we'll find a way to overcome the difficulty.
只要我们不灰心，我们就能找到克服困难的方法。
You can learn anything so long as you set your mind to learn it.
用心学会本领，总能学到手。
You may use the room on condition that you clean it afterwards.
只要你用完后打扫干净，你就可以使用这个房间。
We’ll let you use the room on condition that you keep it clean and tidy.
我们可以让你使用这个房间，条件是你把它保持整洁
(4)、in case表示“假使，万一”
in case既可以引导目的状语从句，也可以引导条件状语从句，等于"if it happens that"。
In case I forget, please remind me of my promise.
如果我忘了，请提醒我所做的承诺。
In case it rains they will stay at home.万一下雨，他们就呆在家里。
(5)、given(that),provided(that),providing(that),supposed(that),supposing
前一个为介词，后四个词为连词，意思相近，都有“如果，只要，假如”等意思。
Given the same treatment again, he is sure to get well.
如果照样再给他治疗一次,他肯定会痊愈。
Given that she is interested in children, I am sure teaching is the right career for her.
考虑到她喜欢孩子, 我可以肯定教书是最适合她的职业
Provided (that) there is no opposition, we shall hold the meeting here.
假如无人反对,我们就在这里开会。
He will do the work providing you pay him.如果你能付费，他可以做这工作。
Suppose/Supposing we can't get enough food, what shall we do? (仅用于疑问句)
假设我们弄不到足够的食物，那我们怎么办？
Supposing he is not at home, what then? 假如他不在家,那怎么办?
(6)、according as(如果;倘若)
You will be able to do it according as you have the courage.
只要你有勇气,你就能做这件事。
注意：条件状语从句和时间状语从句一样，从句的谓语动词不能用一般将来时态、过去将来时态或将来完成时，而要用相应的一般现在时、一般过去时和现在完成时态来替代。
Tell me in case you get into difficulty.遇到困难请告诉我
Supposing he does not come, shall we go without him? 如果他不来,是不是不带他去?
6)、表达“原因”的连接词
原因状语从句是表示原因和理由的从句。连接词有because,for,since,as(前面4词的区别在于语气从强到弱),now (that), considering that, seeing that等。
(1)、because因为….
Because I like it, I do it. 因为我喜欢，所以我才干。
He couldn't have seen me, because I was not there.
他不可能见过我，因为当时我不在那儿。
I did it only because I felt it to be my duty.
I will go to the show because I’m interested in pop music.
(2)、for(conj.因为,由于)
We must start early, for it will take two hours to drive to the airport.
我们得早点动身,因为开车去机场得花两个小时。
(3)、since(conj.因为,既然,由于)
引导的从句大多置于句首，主从句的时态一般相同。
Since you have no licence, you are not allowed to drive.
因为你没有驾驶执照，所以不允许你开车。
Since you are all here, let's try and reach a decision.
既然大家都来了，咱们就设法做出一个决定吧。
Since I have been shopping all day，I feel very tired now.
Since/As the weather is so bad, we have to delay our journey.
(4)、as(conj.因为,由于)，一般多用于句首。
As she was ill, she didn't come to the party.由于病了，她没来参加晚会。
We didn't know what to do as we were just visiting there.
我们不知道该怎么办,因为当时我们仅仅在那里作访问。
区别because, for, since, as
A、because语气最强，表示客观必然原因，强调动作发生的直接原因。用来说明人所不知的原因，一般置于主句之后，也可以放在主句之前，用逗号隔开。在回答"why"引导的特殊疑问句时，或在强调结构It is/was...that...和关联词not...but...引导的原因状语从句中，要用because。另外，because还常和副词just, merely等连用。
He is absent, because he is ill.因为生病，所以他没来。
He is absent, for he is busy.(“生病”是“缺席”的必然原因，“忙”不是必然原因。）
He went to bed early, because he was tired. (直接的理由)
由于他累了，所以他很早就上了床。
He paid me less than the others, only because I'm female.
他付给我比别人少的钱,仅仅因为我是个女的.
It's because he helped you that I'm prepared to help him.
正是因为他帮助过你，所以我乐意去帮助他。
He decided to give up the chance of going abroad, not because he did not want to but because his wife was ill.他决定放弃出国的机会，不是因为他不想去，而是因为他妻子病了。
B、for是并列连词，语气轻,表示非客观必然的原因,是主观可改变结果的原因,甚至是猜测(推断)可能的原因，只用于连接表示原因的分句，因此不能用于句首
He must be ill, for he is absent.(“缺席”不一定是”生病”，只是交流猜测).
【误】For he did not obey the rules, he was punished.
【正】Because he did not obey the rules, he was punished.
由于他不遵守规章制度，他受到了处罚。
The day breaks, for the birds are singing. (不可用because，因为鸟叫不是天亮的原因)
天亮了，因为鸟在叫。
He must be tired, for he went to bed early. (间接的推断)
他肯定累了，因为他很早就上了床。
C、since当原因是显而易见的或已为人们所知，或分析后的推理，就用as或 since。引导的从句大多置于句首，主从句的时态一般相同。
Since I am a boy, let me carry the case.
Since everybody is here,let's begin our meeting.
既然大家都在这,我们开始开会吧.
D、as表示的理由最弱,只是对主句的附带说明,重点在主句.as从句通常放在主句前。
As you don't feel well, you had better stay at home.
As/Since you are busy, you had better not go with us.
既然你工作忙，你就不必跟我们一道去了。
(5)、now that“既然，因为”，that可以省略。
Now (that) dinner is ready, go and wash your hands.既然饭已好了，去洗手吧。
Now (that) you mention it again, I do remember.既然你又提起此事，我倒回想起来了。
Now that you are well again, you can travel.既然价钱恢复了健康，你就可以去旅行了。
Now that she has apologized, I am content.既然她已经道了歉, 我也就满意了。
(6)、 considering(that), seeing(that)，都为连词。
这两个词和since, now that意思相近，都有“鉴于…事实，考虑到…”的意思。
Considering he’s only just started, he knows quite a lot about it.
考虑到他只是刚刚开始, 他对此的了解已经不少了。
Considering he's only been learning English a year he speaks it very well.
考虑到他只学了一年英语,他讲得算是很流利了。
Seeing that quite a few people were absent, we decided to put the meeting off.
由于好些人都没到会，我们决定延期开会。 (seeing后面的that可以省略)
Seeing that you’re already at the door, I suppose I must invite you inside.
鉴于你已到了门口，我想我必须邀请你入内。
注意：considering和given还可用作介词。
Considering his age, the little boy reads very well.(就..而论)
就他的年龄来说，这小孩读得挺好的。
Given her interest in children, I am sure teaching is the right career for her.
考虑到她喜欢孩子, 我可以肯定教书是最适合她的职业
(7)、not that..., but that...
这一结构相当于汉语的“不是因为……而是因为”。
Not that I don't like the film, but that I have no time for it.
不是因为我不喜欢看这部电影，而是因为我没有时间看。
7)、表达“方式”的连接词
方式状语从句是描述动作方式的从句。方式状语从句常由as,as if,as though等词引导，通常位于主句之后。
(1)、as, (just)as…so…
引导的方式状语从句通常位于主句后，但在(just) as…so..结构中位于句首，这时as从句带有比喻的含义，这两个连词的意思是“正如…，就像…一样”。just as(和..一样,像…一样,正如,同样地)比as语气要强一些。多用于正式文体。
Why didn’t you catch the last bus as I told you do?你怎么不听我的赶乘末班公交车呢？
Please do as you are told. (也可说Please do as told.)请按照人家告诉你做的去做。
As water is to fish, so air is to man.我们离不开空气，犹如鱼儿离不开水。
Just as we sweep our rooms, so we should sweep backward ideas from our minds.
正如打扫房屋一样，我们也要扫除我们头脑中落后的东西。
Balloons float in the air just as boats do on the sea.
气球在空中就如同船浮在海面上一样。
注意：在口语中，可用like(<口>conj.如同,好像)来代替as，引导一个方式状语从句。
It was just like you said.情况正如你所说的那样。
She is doing the work exactly like I want her to.
她正在完全按照我要她做的那样在做这项工作。
Do you make bread like you make cakes? 你做面包的方法是不是和做点心一样？
(2)、as if, as though
两者的意义和用法相同,引出的状语从句谓语多用虚拟语态,表示与事实相反;有时也用陈述语态,表示所说情况是事实或实现的可能性较大。汉译常做"仿佛…似的"，"好像…似的"。
They completely ignore these facts as if(as though) they never existed.
他们完全忽略了这些事实，就仿佛它不存在似的。(与事实相反，谓语用虚拟语态。)
He looks as if(as though) he had been hit by lighting.
他那样子就像被雷击了似的。(与事实相反，谓语用虚拟语态。)
It looks as if the weather may pick up very soon.
看来天气很快就会好起来。(实现的可能性较大，谓语用陈述语态。)
The boy plays the piano as though he has a natural ear for music.
这孩子弹起钢琴来好像天生很懂音乐似的。
They talked loudly as if nobody were around.他们大声说话仿佛周围没人似的。
说明：as if/as though也可以引导一个分词短语、to v短语或无动词短语。
He stared at me as if seeing me for first time.
他目不转睛地看着我，就像第一次看见我似的。
He cleared his throat as if to say something.他清了清嗓子，像要说什么似的。
The waves dashed on the rocks as if in anger.波涛冲击着岩石，好像很愤怒。
