连词用来连接词与词、短语与短语或句子与句子。连词不能单独作句子成分，也没有词形变化。连词分为并列连词和从属连词两种。

并列连词

并列连词用来连接句子中担任相同成分的词、短语或分句。常见的有七个单词和四个短语：and, but, or, for(因为), nor, so, yet; both…and…, not only….but also…., either…or…., neither…nor…

1.and用来连接词、短语或分句，表示并列或对称关系：

The man put on his coat and hat, and went out of the office. 那个人穿上外衣、戴上帽子，走出了办公室。

A car and a dictionary are both useful. 汽车和字典都有用处。

I went home and John stayed there. 我回家了，而约翰呆在那里。

2.but连接两个含义不同甚至相反的词、短语或分句，表示转折：

Not everybody is honest and hardworking, but Tom is. 并非每个人都诚实肯干，但汤姆是的。

We tried to persuade her to do it but failed. 我们尽力说服她去做，但没有成功。

3.or表示两者居其一，表示选择：

Which VCD player is better, this one or that one? 哪个VCD更好，这个还是那个?

Are you hungry or not? 你饿了没有?

4.For(因为)只能放在表示结过的分句后面，引导表示原因的分句：

I must be going, for it’s getting dark. 我必须走了，因为天黑了。

He didn’t go there, for he was ill. 他没到那儿去，因为他病了。

5.Both…and…只能用来连接两个并列的词或短语，不能连接句子：

His plan is both easy and practical. 他的计划既容易又实用。

Zhang Yimou is a famous director both at home and abroad. 张艺谋是一位在国内外都著名的导演。

Both this plane and its engines are made in China. 飞机和它的发动机都是中国制造的。

6.Not only…but also…不但能连接词和短语，而且还能连接分句。Also 有时省略。注意not only 位于句首时，主语和谓语需要倒装：

He is not only an actor but also a writer. 他不仅是演员，而且是作家。

He not only read it but also remembered what he had read. 他不但读过，而且记住了所读过的东西。

When we talk about the universe, we mean not only the earth, the sun, and the moon, but (also) all the other things too far away for us to see. 当我们谈到宇宙时，我们不但指地球、太阳和月亮，而且还指一切远得看不见的其他东西。

Not only did he say it but (also) he did it. 他不但说了，而且做了。(倒装)

Not only do the nurses want a pay rise, but also they want reduced hours. 护士们不但要求加工资，而且还要求缩短工时。(倒装)

7.Either…or…表示选择，“或者…或者…”、“不是….就是…”的意思。注意either…or…(整个结构作主语时)句子中的动词通常要和邻近的主语相一致。

Either you are wrong, or I am. 不是你错了，就是我错了。

Either you or he is going to get the job. 不是你就是他将获得这份工作。

Can I borrow either your car or your bike? 我可以借用你的汽车或者你的自行车吗?

If you’re late, you should make an apology to the host either immediately or later. 如果你迟到了，你应该立即或事后向主人道歉。

8.Neither…nor…表示“既不….又不…”的意思。注意neither…nor…整个结构作主语时，句子中的谓语动词通常要和邻近的主语一致：

Neither the students nor I am ready yet. 学生们和我都还没有准备好。

He worked neither for fame nor for money. 他干工作既不图名又不图利。

The girl could neither speak nor write the language. 这个女孩既不会说也不会写那种语言。

9.So(因此)，引导表示结过的分句，原因分句在前。(与for相反)

It’s getting dark, so I must be going. 天黑了，因此我得走了。

I had a headache, so I went to bed early last night. 我头痛，于是昨晚很早就睡了。

10.Yet (然而)，有时和and 一起用，表示吃惊、表示转折，相当于but at the same time, however, nevertheless:

She is vain and foolish, and yet people like her. 她既虚荣又愚蠢，然而人们却喜欢她。

She’s a funny girl, yet you can’t help liking her. 她是个疯疯癫癫的女孩，然而你却禁不住喜欢她。

He worked hard, yet he failed. 他很努力，然而却失败了。

It’s strange, yet it’s true. 这事有点怪，却是真的。

He’s a wealthy, yet honest, businessman. 他是个富有而又诚实的商人。

It is only a little shop and yet it always has such lovely decorations. 那只是个小店，却总是有漂亮的装饰。

You can draw a good horse in five minutes, yet you kept me waiting for a year. 你能在五分钟内画出一匹好看的马，然而你让我等了一年。