连词是一种在句子与句子之间,短语之间以及名词等其他词语之间起连接作用的虚词,它不能单独作句子的成份。按其意义可分为并列连词和从属连词两大类。?并列连词连接的双方是对等的。常有的并列连词有and, both…and, either…or, neither…nor, not only…but also, as well as等。但如果连接的两部分意义不趋向一致,意义有转折的并列连词有:but, however, while (而),only (只不过)。还有表示选择关系的并列连词,如:or, or else, otherwise… 再有的是连接双方,互为因果,或表示前因后果的连词有:for, so, therefore (因此),then等。?从属连词在范围内常常用来连接名词性从句,如:that, if, whether, 其次用来连接状语从句。其中有原因状语从句,常用的连接词有:when while, as, since, before, after, once, as soon as, until, till 连接条件状语的连词有:if, unless, as long as 等,而原因状语的连接词有because, since, as, now that (既然)。目的、结果、方式、比较、地点等状语从句的连接词有:so that, so…that, such…that, as…as, than, where… 它们在句子与文章中几乎无处不见。?具体用法见下表。?
连词用法一览表
种类 功用 例句
并列连词 连接具有并列关系的 词 He knows neither English nor French.
短语 Are you going by bus or on foot?
分句 Mary was a good girl, but she had one shortcoming.
从属连词 引导: 状语从句 I'll do it as you told me.
You will be late unless you hurry.
连接代词和连接副词 主语从句 What he said proved true.
When we'll start has not been decided yet.
表语从句 This is why he didn't come yesterday.
That is where he lives.
宾语从句 The man asked me which I liked best.?
I can't understand why she is so late.
关系代词和关系副词 定语从句 Nicotine is a drug that gets one into the habit of smoking.?
He came last night when I was out.
(二) 正误辨析?
[误] Both my parents are not here. They went to the concert just now.?
[正] Neither of my parents is here. They went to the concert just now.?
[析] 在中both一般用于肯定句中,如用于否定句中,其意义也不同于汉语,如:Both of us are not right. 在中应被理解为"我们俩不都对。"而Neither of us is right。 才能被理解为"我们俩无一正确"。?
[误] He or his parents has some tickets for the film.?
[正] He or his parents have some tickets for the film.?
[析] 由or 连接两主语时,谓语动词应与相临近的那一个主语保持一致。?
[误] You should study hard, and you won't pass the exam.?
[正] You should study hard, or you won't pass the exam.?
[析] or作为连词,这里的意思为"否则"。又如:Hurry up, or you'll be late for school.
[误] Though he is poor, but he is ready to help others.?
[正] Though he is poor, he is ready to help others.?
[正] He is poor, but he is ready to help others.?
[析] "虽然……但是"是中文中的常用结构,但在英文中用了"虽然"则不要用"但是",用了"但是"则不能再用"虽然",二者只可用其一。?
[误] Either you or I are on duty.?
[正] Either you or I am on duty.?
[析] either…or 连接两个主语时,其谓语动词与相临近的一个主语相呼应,这也叫作就近原则。类似的用法还有or, neither… nor, not only…but also等。?
[误] Tom is our English teacher and teaching English in our school now.?
[正] Tom is our English teacher and is teaching English in our school now.?
[析] 并列句中常常在后面的句子中作一些省略,以免重复,但不是所有词都可作任意的省略的。当你连接的是两个系动词时,后面的那个系动词不可省略,也就是讲连接的部分不可省略。
本文来自：逍遥右脑记忆 http://www.jiyifa.net/chuzhong/56705.html
相关阅读：初中英语学习对would的方法总结