连词为什么要学小桥连接两岸。
我们用手连成一个圈圈。
网络把世界各地都连接在一起。
电话把我们和爷爷奶奶外公外婆连接在一起。
观察以上四幅图及其用处，这四种东西有什么共同的作用呢？相信聪明的你已经看出来了，他们都有连接作用，把两个或更多人或事物连接在一起。
其实在语言里，我们也有这种起连接作用的词语，他们的名字叫连词。
他们把词汇、短语、句子连接起来，形成了更为复杂，更为高级，更为美丽的句子。
你能举个例子给老师吗？现在，我们就一起来学习一下连词吧！—我要赶快学一、定义连词是一种虚词，它不能独立担任句子成分而只起连接词与词，短语与短语以及句与句的作用。
二、连词的分类连词分为并列连词和从属连词。
（一）并列连词并列连词用来连接具有并列关系的词，短语或句子。
常见的并列连词有：1.表并列关系的 and, both and, not only but also, neither等。
nor I like swimming,and my mother likes swimming, too. （连接两个句子） Both my mother and I likeswimming. （连接两个并列关系的词语）Not only my mother but also I like swimming.（连接两个并列关系的词语）I want neither going to school nor doing homework.（连接两个短语）2. 表选择关系的or, either等or。
Do you like apples or bananas?Either you or Jack must come here tomorrow.除了表示选择关系外，or 还有“否则”之意。
Hurry up, or you’ ll be late for school.3. 表转折关系的but, yet, while （然而）等。
The watch was cheap, but it goes quite well.这块表虽然便宜, 但走得很好。
He said he was our friend, yet he wouldn他’说t他help是我us们.的朋友，但却不肯帮助我们。
I am doing my homework, while Jean is busy playing games.4.表因果关系的for, so 等。
I had a fever yesterday, so I didn ’twant to do anything.He was late, for the traffic is always busy in the morning.注意： for 表示结果通常不能放句首，也不能单独使用。
Exercise 11. We bought Granny a present, ＿＿＿ she didn't like it.A. butB. andC. orD. so—2. Run quickly, ＿＿＿ we'll miss the early train.A. andB. butC. soD. or3. Which would you like better, tea ＿＿＿ milk?- Tea, please.A. butB. andC. orD. with4. You must start right now, ＿＿＿ you'll miss the train.A. forB. andC. soD. or5. I like fish, ＿＿＿ chicken, ＿＿＿ eggs.A. and, andB. and, withC. /, andD. and, /6. I don ’ t like reading _____ watching TV.What about you? “ I don ’ t like reading all day,like____watchingITV plays. ”A. and, butB. and, andC. or, andD. or, but7. My shoes are worn out, I need new ones.A ． soB ．if C． because D ． and8. Study hard, _____ you will pass the exam.A. soB. forC. butD. and9. Put on more clothes, _____ you ’ ll catch cold.A. andB. forC. orD. but10. We didn't catch the train _______ we left late.A. soB. becauseC. butD. though（二）从属连词从属连词用来引导名词从句和各类的状语从句。
◆ 1. 引导时间状语从句的从属连词(1) 表示“当时候”或“每当”的时间连词。
主要的有when, while, as, whenever 。
如：Don’ t talk while you’ re吃eating饭时不.要说话。
Vegetables are best when they are fresh. 蔬菜新鲜时最好吃。
He came just as I was leaving.我正要走时他来了。
(2) 表示“在之前 (或之后 ) ”的时间连词。
主要的有before, after 。
如：Try to finish your work before you leave.离开前设法把工作做完。
After we have finished tea, we will sit on the grass.喝完茶之后我们将坐在草地上。
(3) 表示“自从”或“直到”的时间连词。
主要的有since, until, till 。
如：She’ s been playing tennis since she was eight她.从八岁起就打网球了。
Hold on until I fetch help.坚持一下，等我找人来帮忙。
—(4) 表示“一就”的时间连词。
主要的有as soon as, the moment, once, no sooner than, hardly等。
如： whenI ’ ll let you know as soon as I hear from her.我一接她的信就通知你。
The moment I have finished I’ ll give you我a一call干完.就给你打电话。
Once you begin you must continue.你一旦开始,便不可停下来。
(5) 表示“上次”、“下次”、“每次”等的时间连词。
主要的有e very time( 每次 ) ，each time(每次 )，(the) next time( 下次 )， any time(随时 )， (the) last time( 上次 ) ，the first time( 第一次 ) 。
如：I ’ ll tell him about it (the) next time I see him. 我下一次见到他时，我就把这个情况告诉他。
We lose a few skin cells every time we wash our hands.每当我们洗手的时候，我们都要损失一些皮肤细胞。
You can call me any time you want to.你随时都可以给我打电话。
注意：every time, each time, any time 前不用冠词， (the) next time, (the) last time 中的冠词可以省略，而 the firsttime 中的冠词通常不能省略。
◆ 2. 引导条件状语从句的从属连词。
这类连词主要有if, unless, as [so] long as, in case 等。
如：Do you mind if I open the window?我开窗你不介意吧?Don’ t come unless I telephone.除非我打电话，否则你别来。
As long as you’ re happy，itdoesn’ t matter what you do只.要你高兴，你做什么都没关系。
In case it rains they will stay at home.万一下雨，他们就呆在家里。
◆ 3. 引导目的状语从句的从属连词。
主要的有in order that, so that, in case, for fear 等。
如：He raised his voice so that everyone could hear. 他提高了嗓音，以便每个人都能听见。
Take your umbrella (just) in case it rains.带上雨伞，以防下雨。
She repeated the instructions slowly in order that he should understand. 她把那些指示慢慢重复了一遍好让他听明白。
◆ 4. 引导结果状语从句的从属连词。
主要的有so that, so that, such等that。
如：I went to the lecture early so that I got a good seat. 我去听演讲去得很早 , 所以找个好座位。
Ihad so many falls that I was black and blue all over. 我摔了许多跤，以致于全身都是青一块紫一块的。
He shut the window with such force that the glass broke.他关窗子用力很大, 结果玻璃震破了。
◆ 5. 引导原因状语从句的从属连词。
主要的有because, as, since等。
如：He distrusted me because I was new. 他不信任我，因为我是新来的。
Since we ’ ve no money, we can’由tbuy于我it们.没钱，我们无法购买它。
◆ 6. 引导让步状语从句的从属连词。
主要的有although, though, even though, even if, while, however, whatever, whoever, whenever, wherever 等。
如：Although they are twins, they look entirely different.他们虽是双胞胎, 但是相貌却完全不同。