说到连词大家可能最先想到的就是“and”“or”“but”，除了这些还有哪些连词呢，这些连词的结构、用法又是怎样的呢，下面就来详细了解一下初中英语连词的具体用法。
连词的定义
连词是连接字、短语、从句与句子的词，是虚词，因此它不能独立担任句子成分。连词主要分为两大类：并列连词和从属连词。并列连词用来连接并列关系的词、词组或分句。它包括：and，or，but，so，for，both…and，either…or，neither…nor，not only…but also。
从属连词用来引导从句，它包括： that， when， till， until， after， before， since，because，if，whether，though，although，so…that，so that，in order that，as soon as
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…nor等。
(2)表选择关系的or, either…or等。
(3)表转折关系的but, while等。
(4)表因果关系的for, so等。
知识点概述
并列连词和从属连词的用法
连词是连结单词、短语、从句或句子的虚词， 在句子中不单独作句子成份。
连词按其性质可分为：
1．并列连词 如：and, or, but, for, 等， 连接并列的词与词，短语与短语，句子与句子。
如：Rice and potatoes are common foods. （词与词）
Today we can travel by plane. （短语与短语）
Many trees lose their leaves in winter, but evergreen trees do not. （ 句子与句子）
关联连词是一类成对使用的连词
如：both……and……, not……but…….
not only……but also…… not only…but… as well
either……or…… neither……nor……
关联连词必须后接同样的语法结构。
如：Either the windows were opened or the door was opened.
2．从属连词 如：that, whether, when, because, though 等， 用以引导名词性从句和状语从句。
3．从属连词引导的从句不可以被断成一个句子。 如果断开，就错了。
如：When the alarm clock rang. （不完整）
4． though (although)引导让步状语从句，because 引导原因状语从句， 所以though(although)不能和并列连词but ，because 不能和并列连词 so一起使用。 只能单独使用。
复习时需要注意的要点
（1）表示选择关系的连词，连接的双方只取其一。常用连词有or, either...or, otherwise
例如：
1）You can go to Beijing either today or tomorrow
2）You must get up early or you won’t catch the early bus.
（2）表示转折关系，连接的双方构成对比，意义上有转折。常用连词有but, however, while, only
例如：
1） His brother is fond of football while he likes basketball.
2） You can watch TV, but you must finish your homework first.
（3）表示联合关系，联合的双方是对等的，意义上趋向一致。常用连词有：and, both...and, neither...nor, not only...but also, as well as, together with
例如：
1） To study English well, we need both diligence and careful.
2） That horse is not only the youngest among the five, but also runs the fastest.
（4）表示因果关系，连接的双方，互为因果，或者前因后果，或者前果后因。常用的连词有：for, so, therefore
例如：
1） It must have rained, for the ground is wet.
2） You are in the right, therefore they should support you.
实战演练
一、例题选讲
例1 he did not know much English，he got out his dictionary and looked up the word.
A． As B． For
C． Since D． Because
答案： A
提示： for，because和as虽皆可作连词用，表示“因为”，但用法有些区别。for引导的分句总是置于另一分句之后，常常对前一分句加以解释，两个分句之间，总是用逗号分开。because引导的原因状语从句时，往往以why问句，语气比较重，传递的往往是对方未了解的新信息。as引导的原因状语从句时，往往是对方也知道的信息。本句是他拿出词典查，显然，“他知道的英语单词不多”，这是明摆着的事，所以用as最恰当。
例2 you don't feel well，you'd better stay at home．
A． Because B． Since/If
C． For D． Now
答案： B
例3 I don’t know he has received the package.
A． if B． when
C． what D． how many
答案： A
提示： if表示是否，when不能与现在完成时连用。
例4 Come tomorrow, I will give it to you.
A． or B． and
C． though D． if
答案： B
提示： and在此处解释为“那么”，表示递进关系。
例5 The teacher his students likes football.
A． and B． as well as
C． and also D． also
答案： B
提示： as well as 连接两个主语用靠前原则。
例6 We were having lunch some one knocked at the door.
A． as B． a soon as
C． when D． while
答案： C
填入适当的连词。
1. My brother is ill, ________ I have to stay at home.
2. The film must be very interesting, ________ many people are buying tickets in line.
3. My computer is new, ________ it is too expensive.
4. She felt hungry, ________ she didn’t have breakfast.
5. A customer came in, ________ I stopped my work.
6. He has a lot of money, ________ he spends little.
7. Come here early, ________ you can’t see him.
8. Take some medicine, ________ you will feel better.
9. There are a lot of stories about the UFOs, _______ no one knows whether they are true or not.
10.Put on your coat, ________ you will catch cold.
11.She got a “C” in English test, ________ she had tried his best.
12.My little cousin can _________ read ________ write.
13.Please call me _______ you need my help.
14._____you have a few more days’ rest, you’ll feel better.
15._____ my father ______ my mother is a doctor. They are teachers.
16.I really don’t know ______ it is going to rain or not this afternoon.
17.You may ______do it yourself ________ leave it to me.
18.Hurry up, ______ you’ll miss the next bus.
19.Li Ming was a brave boy, ______ he had one shortcoming.
20.It’s a fine day, ____ we have a wonderful time.
21.I don’t know _______ she can speak Russian or not.
22.We haven’t decided _____ and ______ we shall meet next time.
23.That’s ______ they didn’t pass the exam.
24._______ you are right, _____ he is.
25.He ______ _____ read the book ______ _______ remembered what he read.
参考答案
1.so 2.for 3.besides 4.as 5.so 6.but 7.or 8.and 9.but 10.or
11.though 12.neither, nor 13.if/when 14.if 15.neither, nor 16.whether
17.either, or 18.or 19.though 20. 21.whether 22. 23.why
