一、连词的定义
用来连接词、短语、从句与句子的词叫连词(Conjunction)。 二、连词的种类
根据在句子中所起的作用，连词可分为并列连词(Coordinative Conjunction)和从属连词(Subordinate Conjunction)两类。
（一）并列连词
连接具有并列关系的词、短语或句子的连词叫并列连词。
根据其意义，并列连词又可分为表示联合、转折、选择和因果等四种关系的连词。 1. 表示联合关系的并列连词 表示联合关系的并列连词有：and（和），both and（既……又……），neither…nor…（既不……也不……），not only…but also，（不但……而且……），as well as （除…… 外……也……）例如： I am a teacher and he is a doctor．我是老师，他是医生。
He has experience as well as knowledge.（= He has knowledge but also experience.）他既有知识，又有经验。 Neither I nor he has seen the film．我没看过那部电影，他也没看过。 2. 表示转折关系的并列连词 表示转折关系的并列连词有：but（可是，但是），while （ 而 ；然而 ），still（但是，然而），yet（可是），however（然而，但是），whereas（而）,nevertheless（然而，不过）。例如： I am willing，yet unable．我心有余而力不足。
He is short，while his brother is tall．他个子矮而他兄弟个子高。 He worked hard， however， he failed.他很努力，然而还是失败了。（however可置于句首、句中或句末） The pain was bad，still he did not complain. 痛得厉害，可是他并不呻吟。 3. 表示选择关系的并列连词
表示选择关系的并列连词有: or（或）， or else（否则）， otherwise（要不然），either…or…（或……或……，不是……就是……），rather than（而不，也不）。例如： John or I am to blame。不是约翰，就是我该受责备。
Seize the chance， otherwise（or else） you’ll regret it．抓住机会，否则你会后悔的。（otherwise，or else常接在祈使句后面）
You can either stay at home or go fishing. 你可以呆在家里，或是去钓鱼。
He went rather than stay as an unwelcome guest．他走了，不愿呆着做个不受欢迎的客人。 4. 表示因果关系的并列连词
表示因果关系的并列连词有：so（所以），for（因为）。例如： It is morning，for the birds are singing．是早晨了，因为鸟叫了。 It was late，so I went home，天已晚了，因此我就回家了。 注：then（那么．因而），thus（因而），hence（因此），therefore（因此，所以）等副词常可放句首表示因果关系。如：
He was busy，therefore he could not come.他忙，所以不能来。 He studied hard, thus he got a full mark.他很用功，因而得了满分。
His car broke down，thus he was late for work．他的车坏了，因此他上班迟到。 It is winter now, hence the days will be shorter.现在是冬天，因此白天会短些。 巩固练习
一、用所给的并列连词填空，每个连词只能使用一次： Either, or but and for neither, nor or yet so 1. British English American English are more or less the same. 2. It rained hard, she came on time.
3. You can choose this one that one, but not both. 4. My glasses had been broken, I could not see it clearly.
5. There are many trees in the village, the villagers still plant some more every year. 6. The cars produced by this factory will be supplied to people all over the world sooner later.
7. We should build a house on sand along the lines where two of the earth's plates join together. 8. It's faster to buy airplane tickets, the CAAC has bought a new computer.
（二）从属连词
用来连接主句和从句的连词叫从属连词。
从属连词可分为两类：引导名同性从句的从属连词和引导状语从句的从属连词。 1.引导名词性从句的从属连词
引导名词性从句的从属连词有连接词that，whether和if，这些连接词在句子中不充当任何句子成分；连接代词主要有who , whose，which，what等，它们在句中可作主语、宾语、定语等；连接副词主要有when，where, how why等，它们在句子中可作状语（祥见名词性从句）。如：
We know (that) the earth goes round the sun. 我们知道地球围绕太阳运转。（宾语从句） What we need is more time. 我们需要的是更多的时间。（主语从句） That’s what I want. 那就是我想要的。（表语从句）
The news that our team had won was very exciting. 我们队赢了，这消息令人十分振奋。（同位语从句） 2.引导状语从句的从属连词 a.引导时间状语从句的从属连词 when（当……时），while（在……期间），as（当……时，一边……一边），after（在……之后），before(在……之前)，since(自从……以来)， till／until（直到，直到……才），once，（一旦……），a。 soon as(一……就……)， the moment／instant（一……就……）， no sooner (一 …… 就 ……)，hardly…when（刚一 …… 就 …… ）等。 例如：
Once you begin, you must go on.你一开了头，就应当继续下去。 When it rains, I go to school by bus.下雨时，我坐公共汽车上学。 b.引导原因状语从句的从属连词
as（由于）, because（因为）, since（既然）等。
He didn’t go to school because he was ill. 他因为生病没去上学。
Since everybody is here, let’s begin．既然大家都在这里，我们开始吧。 c.引导地点状语从句的从属连词 where（在……地方），wherever（无论在……哪里）等。
Wherever she may be，she will be happy．她无论在什么地方都快乐。 Where there is a will，there is a way有志者，事竟成。 d.引导条件状语从句的从属连词 if （如果），unless（除非），so／as long as（只要）等。例如：
He will not come unless he is invited．除非被邀请，否则他是不会来的。
You’ll be late for the class if you don’t hurry．如果你不快点，你就会上课迟到。 e.引导目的状语从句的从属连词 that（以便）， so that（为了）， in order that（为了）， less（以防，免得），in case（以防，免得）等。 例如：
She took medicine on time in order that she might get well soon．为了快点病好，她按时吃药。 I came here that I might take a good look at the new bridge．我来这儿，为的是好好看看新大桥。 f.引导结果状语从句的从属连词 so（结果）， so that（结果）， so … that／such…that（如此……以致），that（以致）等。例如： It was very cold，so that the water in the bowl froze．天气很冷，碗里的水都结冰了。 He is such a good student that we all like him．他是个好学生，我们都喜欢他。 g.引导让步状语从句的从属连词 though／although（虽然），as（虽然），even if／even though（即使），however（无论怎样），whatever(无论什么)，whoever(无论谁)，no matter how/what/which/…（无论多么／什么／哪一个／……）等。例如： Even if you were here yesterday, you couldn’t help him. 即使昨天你在这，你也帮不了他。 Though he is old，he still works hard．虽然他老了，可是他还是努力工作。 h.引导方式状语从句的从属连词 as（正如），as if／as though（好像，似乎）等。 例如：
He speaks English as if he were an Englishman、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把。 i.引导比较状语从句的从属连词 as（如……），as…as…（像……一样），not so…as．．、（与……不一样），than（比）等。例如： He works harder than before．他比以前更努力工作。
His elder sister is as tall as his mother．他姐姐和他母亲一样高。 三、部分连词的用法比较 （－）when和while
两个词都可以表示“当……时”，引导时间状语从句。when引导时间状语从句的谓语动词既可以是延续性的，也可以是终止性的；while引导时间状语从句的谓语动词只能是延续性的。例如： 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．当他在做家庭作业时，我走了进来。 While／When I was in the town，I saw him twice.（当）我在城里时，见过他两次。 Strike while the iron is hot．趁热打铁。
when还可译作“这时”，while可译作“而”。
He was playing football outside when it began to rain．他在外面踢足球，这时开始下起雨来。 He is tall while his elder brother is short.他个子高，而他哥哥个子矮。 （二）though和 as
两个词都可表示“虽然”，引导让步状语从句。though引导的从句用正常语序；as引导的从句要用倒装语序，即把从句中的表语、状语或动词原形放在as之前。 比较下列几个句子：
1. 尽管天气冷，可他仍继续工作。 Cold as it was，he went on working． Though it was cold，he went on working. 2. 虽然他还是个孩子，可懂很多事情。 Child as he is，he knows a lot．
Though he is a child，he knows a lot．
3. 尽管你读得快，你也不能在三天内读完这本书。 Fast as you read，you can’t finish the book in three days.
Though you read fast，you can’t finish the book in three days． 4. 不管怎样努力，他还是摆脱不了困难。
Try as he might，he couldn’t get rid of the diff1culty
Though he might try，he couldn’t get rid of the difficulty。 （三）because，as，since和for 四个词都可以表示“因为”的意思。
for是并列连词，语气最弱，对前面分句加以解释或表示推断的原因。引导的分句一般置于句末，从句前要用逗号。
because表示产生某结果的必有原因，语气最强，引导的从句可以置于句首或句末，放在句前时通常用逗号。 as表示原因时，语气不如because那么强，可译为“因为，由于”，引导的从句常置于句首。
since可译为“既然”，往往表示一些显而易见的原因，语气不如because强，引导的从句常置于句首。例如： It must have rained last night, for the ground is wet.昨晚一定下了雨，地面是湿的。 As she was in a bad mood，we left her alone．由于她心情不好，我们不去打扰她了。 He is absent from school because he is ill．因为生病，他没来上课。
Because/As it was wet, we went there by bus. 因为下雨，我们乘车去那儿。 Since everybody is here，let’s begin．既然大家都到了，我们开始吧。
Since a lot of people make mistakes in life，Mr. Smith wanted to give John a chance. 既然很多人在生活中都会犯错误，史密斯先生想给约翰一个（改过的）机会。 （四）if和whether
1. 表示“是否”时两个词都能引导宾语从句
I wonder if／whether you can examine him now．不知你现在是否可以给他检查一下。 注1：如果主句的谓语是短语动词，用whether，而不用if.
Everything depends on whether we have enough money．一切都取决于我们是否有足够的钱。 注2：某些动词（如discuss）后的宾语从句，用whether，而不用if. They discussed whether they should help her.他们商议他们该不该帮助她。 注3：宾语从句移置于句首时，用whether，不用if
Whether it is true or not，I can’t say．这是不是真的，我不敢说。 注 4：宾语从句为否定形式时，通常用 if，而不用 whether。 I asked her if he wouldn’t come．我问她他是不是会来。
2. if可译为“如果”引导条件状语从句
If I were you，I would not go．如果我是你，我就不去。 3. whether可译为“不管，无论”，引导让步状语从句。
Whether he agrees or not，I shall do that．不管他同意与否我都要做这事。
4. whether可以引导主语从句、表语从句、同位语从句，接不定式，或接or not等（if则不能） Whether he will come or not is unknown. 他来不来还不知道。（主语从句） The question is whether it is worth doing．问题是这事是否值得做。（表语从句） I have no idea whether he is there. 我不知道他是否在那。（同位语从句） I don’t know whether he will do it or not．我不知道他是否会做这事。（接 or not） She hasn’t decided whether to go or not．她还没有决定去还是不去。（接不定式）
巩固练习
二、用所给的从属连词填空，每个连词只能使用一次： by the time every time where since while when 1. BBC English broadcasts programs for China 4 it has explanations in Chinese. 2.The country singers sang they were playing the guitar.
3. Quite a few American presidents have been shot the USA was founded. 4. she got up, a morning newspaper had been delivered to her house. 5. I see a film acted by Charlie Chaplain, I can't help laughing. 6. Put the coins they were just a moment ago. 三、用所给的从属连词填空，每个连词只能使用一次： whether since though no matter what unless l. We'll hold the sports meet next Friday it rains. 2. He will not give up happens.
3. He will go to study abroad his parents agree or not.
4. you've changed the suit of wrong size, I needn't return the money to you. 5. He came back on time the bridge was washed away by the floods. 四、用所给的从属连词填空，每个连词只能使用一次： as if in order that so, that so that that whether as so, as as … as than 1. A hurricane which happens during the day time has more deaths one which happens at night. 2. She threw the leg of pork to the lion far she could. 3. It is not safe to remain in the house to go into a field.
4. People are told not to eat so many hamburgers westerners do.
5. Many people in the street watched the fire they were watching an exciting play. 6. The boy jumped onto a big table he could see everything clearly.
7. The necklace cost Pierre and Mathilde much money they had to work hard for ten years to pay back the money.
8. The doctor asked Mr. King to remove his trousers he could examine his legs. 9. It is known the Chinese have been making paper for two thousand years.
10. Marx was not too sure the English grammar and some idioms were used correctly in his articles. 五、选择正确的连词填空，每个连词只能使用一次： than, that, if, because, while, until, so that, or, since, when 1.The train had left Alice hurried to the railway station. 2.Jack has leaned a lot he entered school.
3.Mr. Green didn’t begin his class all the students arrived. 4.Some people waste food others haven’t enough. 5.John had to walk home the last bus had gone. 6.Be careful you will break your neck.
7.He worked very hard he could catch up with the other classmates. 8.You may go you finish it early.
9.Do you know Abraham Lincoln had been a lawyer before he was elected president of the United States? 10. It’s much better it was yesterday.
参考答案： 二、
1. and 2. but 3. either… or 4. so 5. yet 6. yet 7. neither… nor 8. for 三、
1. When 2. 四、
1. unless 2. 五、
1. than 2. so … that 8. 六、
1. when 2. 9. that 10.
while 3. since 4. By the time 5. Every time 6. where no matter what 3. whether 4. Since 5. though as … as 3. so … as 4. as 5. as if 6. in order that 7. so that 9. that 10. whether since 3. until 4. while 5. because 6. or 7. so that 8. if than
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