英文的连接词和介系词都是简短的一个小字，但可不要弄混了，它们在语意表达上的功能是不相同的。连接词顾名思义就是连结句子中的字汇和子句的意义，依照使用的类型共分为三种 :
A. 对等连接词：
and / but / or / so / for / yet
B. 配对连接词：
both …and / not only … but also / either … or / neither … nor
C. 从属连接词：
表示时间 after, before, when, while, as soon as, as long as, so long as, since, until
表示原因 as, because, since, now that
表示条件 if, unless, whether or not, even if, in case, in the event that
表示对比 although, though, even though, while, whereas
对等连接词：功能在于连结词性相同的生字和句子
and / but / or / so / for / yet
and 和，并，且，及，然后
Steve and his friend are coming to dinner. ( 连接名词)
Steve和他的朋友将要来吃晚餐
The old man is kind and generous. ( 连接形容词)
那位老先生很仁慈和慷慨
Anna spoke angrily and bitterly about the war. ( 连接副词)
Anna 愤怒而痛苦地谈起那战争
I enjoy watching movies and playing tennis in my free time. ( 连接动名词)
在我的休闲时间，我喜欢看电影和打网球
Susan stood up , wore her coat , and walked out. (连接动词)
Susan站起来，穿上外套，并走出去。
It was raining hard , and there was a strong wind. ( 连接句子)
雨下得很大，风也很强。
but 但是，不过，而
He is not a writer but a painter . ( 连接名词)
他不是一位作家，而是一位画家。
These shoes are old but comfortable . ( 连接形容词)
这鞋子老旧但很舒适
Jerry looked for his cell phone , but couldn't find it. ( 连接句子)
Jerry在找他的手机，但找不到。
I dropped the big vase , but it didn't break. ( 连接句子)
我掉落了大花瓶，但它却没有破掉。
The directions were not clear , but I found the bookstore anyway. ( 连接句子)
方向不清楚，但我还是找到了那家书店。
or 或者，还是，否则
Would you like some tea or coffee ? ( 连接名词)
你想要一些茶或咖啡吗？
Is lemon juice sweet or sour ? ( 连接形容词)
柠檬汁是甜的还是酸的？
Gary wants to watch TV or ( to ) listen to some music. ( 连接不定词)
Gary想要看电视或听一些音乐
You had better hurry , or you'll be late. (连接句子)
你最好赶快一点，否则你要迟到了。
Do you have to go to work on Monday , or is Monday a holiday ? ( 连接句子)
你星期一要去上班吗？或者星期一放假？
so 所以，因此，结果
Jenny was tired , so she went to bed early. ( 连结句子)
Jenny累了，所以她早早上床睡觉了。
Allen didn't study , so he failed the test. ( 连结句子)
Allen没念书，所以他考试不及格。
It was hot , so we went swimming. ( 连结句子)
天气很热，所以我们去游泳。
Lisa was ill , so she missed the class. ( 连结句子)
Lisa生病了，所以她没去上课。
Mike had to study for a test , so he went to the library. ( 连结句子)
Mike需要准备考试，所以他去了图书馆。
for 因为，由于，为了…的缘故
Annie is in serious legal trouble , for she had no car insurance at the time of the accident. ( 连结句子)
Annie 遇到了严重的法律难题，因为发生车祸时，她的车没有保险。
The little girl hid behind her mother's skirt , for she was afraid of dogs. ( 连结句子)
小女孩躲在她妈妈的裙子后面，因为她会怕狗。
Lucy has to start early tomorrow , for it will take three hours to drive to the airport. ( 连结句子)
Lucy 明天很早就得出发，因为要开车3小时才能抵达机场。
We have to go to the grocery store , for there is nothing in the house to fix for dinner. ( 连结句子)
我们需要去食品杂货店，因为家里没东西可作晚餐了。
I wore a coat , for the weather was cold. ( 连结句子)
我穿了外套，因为天气很冷。
yet 然而，却， 但是
Julie didn't study , yet she passed the exam. ( 连结句子)
Julie没念书，但却通过了考试。
Rick's academic record was outstanding , yet he was not accepted by the university. ( 连结句子)
Rick的学业成绩非常优异，但他却没被大学录取。
David didn't know how to swim , yet he jumped into the swimming pool. ( 连结句子)
David 不知道如何游泳，但他却跳进了游泳池。
I don't like the leading actress , yet the movie was really good on the whole. ( 连结句子)
我并不喜欢女主角，然而这电影整体来说非常好。
I washed my hands several times , yet they still looked dirty. ( 连结句子)
我洗手洗了好几次，但它们看起来还是很脏。
