概念引入
连词就是把两个或两个以上相关的单句组合起来的词语。连词用来连接词、短语、从句或句子，是一种虚词，不能单独作句子成分；连词可以使句子与句子联系比较紧凑，因而使上下文更加连贯。连词在英语中的运用比在汉语中广泛得多。在汉语中常把两个或更多的词句等连起来而不用连词，但在英语中却很少有这种情况。
Are we to have a meeting today or tomorrow? 我们是今天开会，还是明天？（连接词） He did not come this morning but yesterday evening. 他不是今天早晨来的，而是昨天晚上来的。（连接短语） She set out soon after dark and arrived home an hour later. 她天黑后不久出发，一小时后到家。（连接短语）
We’re going to the bookstore in John’s car. You can come with us or you can meet us there 我们乘约翰的车去书店。要么你和我们一起去，要么以后到书店找我们。（连接句子） I don’t know whether/if he will come. 我不知道他是否会来。（连接句子）
later.
语法讲解 连词的分类
1. 连词从本身含义及所连接的语言单位之间的逻辑关系，可分为并列连词和从属连词。 并列连词是用来连接彼此并列的词、短语、从句或句子的词，常用的：and, or, but, for, therefore, not only...but also等。
从属连词通常引导名词性从句即主语从句、宾语从句、表语从句、同位语从句（that, whether, if等）以及状语从句（when, while, though, because, if, so that等）。 2. 连词从句子结构形式上分为：
简单连词：and, but, when, for, if, where等。 关联连词：both...and, neither...nor, as...as等。 短语连词：as if, so that等。
分词连词：given, considering, supposing等。 并列连词
并列连词可表示多种意义，但主要有四种，即表示并列、转折、选择、因果等。注意并列连词在句子中位置比较固定，定位于所连接的语言单位之间，两个并列连词不能并用,而可以与从属连词并用。 表示并列关系的并列连词 and的用法
1. 可以连接两个词，多用于肯定句中。
Go and fetch something to eat.（连接两个动词如go, come等表示目的）去取些吃的东西来。 He started to shout and sing.他开始大叫并唱歌。
Read it slowly and clearly.慢慢念，念清楚。 The balloon flew higher and higher.气球越飞越高。
You can meet teachers and students.你会见到许多老师和学生。
Proper diet and exercise are important to health.适当的饮食和锻炼对健康很重要。 2. 连接两个句子，表示因果、对比、条件、假设、目的等。 They didn’t catch the bus, and had to stay in a hotel for the night. 他们没赶上汽车，只好在旅馆过夜。（因果） Mary likes music and Lily is fond of sports. 玛丽喜欢音乐，莉莉爱好体育运动。（对比） Work hard and you will succeed.
（条件，前面部分常为祈使句）如果你努力工作，就会成功。 One more week and we’ll accomplish the task. 再一星期，我们就完成任务。（条件） both...and的用法
both...and意为：“不但……而且……； 既……又……”，是并列连词，可以并列主语、宾语、表语、状语、谓语等成分。并列主语时谓语动词用复数形式。 Both New York and London have traffic problems. 纽约和伦敦都存在交通问题。
The secretary both speaks and writes Spanish. 这位秘书不但能讲而且能写西班牙语。
Both teaching and research work are making great strides. 教学与科研都在大踏步前进。
The delegates visited both New York and Boston. 代表们既访问了纽约，又访问了波士顿。 She both plays the piano and sings. 她既会弹钢琴又会唱歌。
Both she and the headmaster were pleased with the boy. 她和校长都喜欢这个男孩。
The situation both at home and abroad is in our favor. 国内外形势对我们都很有利。 not only...but also的用法
not only...but also意为：“不但……而且”，是并列连词，可以连接两个词，也可连接两个句子。其中，but also中的also可以省略。
not only...but also可以连接句中所有的成分，连接并列主语时，其谓语动词根据就近原则，与所靠近的成分保持数的一致。
Not only the students but (also) their teacher is enjoying the movie. 不仅学生们津津有味地看着这部电影，而且他们的老师也是如此。 He can speak not only French but (also) English.
他不但会讲法而且会讲英语。
He not only had seen the film but also remembered what he had seen. 他不仅看过那部影片，而且记得影片的内容。
not only...but also可以连接两个句子，not only位于句首时， not only后的句子要倒装。 Not only is he a scientist, but he is also a fighter. 他不但是位科学家而且还是名战士。
Not only was everything he had taken away, but his citizenship. 不仅他的一切被拿走，而且他的国籍也被取消。 as well as 的用法
as well as起连词作用，表示“同、和、也”等。
The editors as well as the proofreaders are working overtime. 编辑和校对者都在加班工作。 I have read his novels as well as his plays. 我读过他的小说和剧本。 并列连词when的用法
when作为并列连词，意为“就在那时” I was about to leave when the telephone rang. 我刚想走，突然电话铃响了。
We played outside till sunset, when it began to rain. 我们在户外一直玩到太阳下山, 那时天下起雨来了。 表示选择关系的并列连词
此类并列连词主要有or, or else, either...or, otherwise，neither...nor, not nor等。
or可以连接两个的词，多用于否定或者疑问句中。主语的人称、数不一致时, 动词随着接近的主语而变化。
John or you are in Class Two. 约翰或者你在二班。 He never smokes or drinks. 他从不吸烟，也不喝酒。 Will you have tea or coffee? 你喝茶还是喝咖啡？
Are you leavening for Beijing by train or by plane? 你是坐火车还是坐飞机去北京？
She will be back either today or tomorrow.她不是今天回来，就是明天回来。 Would you like a cup of coffee or shall we get down to business right away? 你愿意先喝咖啡还是我们谈正事。 Put on your overcoat, or you will catch cold. 穿上你的大衣，不然你会着凉。 He must pay the debt or else go to prison.
他必须还债,否则就得去坐牢。（or和else连用） Hurry up, or/or else we’ll be late for the meeting. 赶快，否则我们开会要迟到的。
注意：or, or else, otherwise三者相比，or else语气较or强，而otherwise语气则最强。 Make haste, or (else) you’ll be late. 快点, 要不然就来不及了。
Let’s begin; otherwise, we will fall behind. 我们这就开始吧，不然会落后的。
I would like you to change this blouse, or else give me my money back. 我想要你换掉这件衬衣，要不把钱退给我。 表示转折关系的并列连词
这类连词连接两个含义不同的甚至是反义的词、短语或分句。常见的还有yet(然而)，while(而)，however(可是)等。其中while与but的区别在于：while表示对比，而but表示意义正好相反。
Learning the guitar isn’t difficult, but you have to practice. 学弹吉它并不难，但你得练习。
The changes in the city will cost quite a lot, but they will save us money in the long run. 改造城市需要花费很多的钱，但从长远来看还是省钱。 Excuse me for breaking in, but I have some news for you. 请原谅我贸然闯入，但我有消息告诉你。
In some Asian countries, nodding the head means not “Yes” but “No”. 有些亚洲国家，点头并不表示“是”而是表示“不”。 He was in deep trouble, yet he didn’t lose heart. 他深陷困境，然而他没有丧失信心。
Rick was very successful. However, the last few years of his life were not happy ones. 瑞克非常成功，然而他的晚年并不幸福。 You like sports, while I’d rather read. 你喜欢体育而我却喜欢读书。
They were surprised that a child should work out the problem, while they themselves couldn’t. 他们很吃惊一个孩子能把这个题解出来而他们却不能。
She thought I was talking about her daughter, while in fact I was talking about my daughter. 她认为我是在谈论她的女儿，而事实上我在谈论我女儿。
注意：not...but在连接主语时，谓语动词要按就近原则，与靠近的主语在人称和数上保持一致。
Not the manager but the workers are hoping to do that. 不是经理而是工人们希望那么做。 Not you but I am a teacher. 不是你而是我是老师。
but与however区别
首先however位置较灵活，常用逗号与主句隔开，而but通常不用；其次but常用于I’m sorry/Excuse me, but...中，而however不可。 1.
but表示转折、对比、对照，语气最强，常位于句子的开头。 His mother won’t be there but his father might. 他母亲不会在那儿，但他父亲也许会在。 口语中在上下文语境中会用于句首。
“I read it in a newspaper.” “But newspapers are not always right.” “我从报纸上读到的这则消息。”“但是报纸并不总是正确的。” I’m sorry, but I can’t help you with the problem. 很抱歉，我不能帮助你解决这个问题。
2. however作连词时，其引导的从句放在主句前，也可放在主句后，表示“不管……”。另外，however常用作副词，表示“然而”，这时，however可位于句首、句中、句末，但必须有逗号与主句隔开。however还可表示“无论怎样”。
He was feeling bad. He went to work, however, and tried to concentrate. 他感觉不舒服，但他仍然去上班，并努力集中精力。 They had worked hard. However, they didn’t finish the task. 他们很努力工作，然而没有完成任务。 while与although区别
1. while可作从属连词，表“虽然”，此时可与although互换。while可作并列连词，表“然而”，强调前后是对比的关系，所引导的句子不能位于句首。 While I haven’t seen him，I have regarded him as my friend. 虽然我没有见过他，我一直把他当作我的朋友。
I do every single bit of housework while my husband Bob just does the dishes now and then. 我做所有的家务，而我的丈夫鲍勃只是偶尔刷刷碗。 I learned a lot of French while I was in Paris. 在巴黎时我学了很多法语。
2．although表“虽然”，引导从句时不能与but共用，但可与still，yet连用。
Although she hates her stepmother，now and then she goes to see her for the love of her father. 尽管她不喜欢她的继母，但为了她对父亲的那份爱，她还是时常去看望她。 Although they are proud，they are afraid to see me. 他们虽然傲慢，但他们怕见我。 表示因果关系的并列连词 并列连词for的用法
for可以表示“因为”但引导的不是从句，而是分句，对前面情况加以解释，常用逗号把它和前面的分句分开，这在书面语中计较多见（口语中多用because, as , since等）： The days were short, for it was December. 白天很短，因为已经是十二月。
它还可以表示为什么有前面的看法(此时不能用because, as, since)： She must have gone out early, for she had not shown up at breakfast. 她肯定一早出去了，因为她没来吃早饭。 so的用法
so 表示结果，可译为“因此”、“所以”： Our cases were heavy, so we took a taxi. 我们的箱子很重，因此我们坐了出租车。 注意：
therefore 为副词，也表示同样的意思，可放句前： He had gone; she therefore gave the money to me. 他走了，于是她把钱给了我。
hence 也是副词，也表示类似意思，多用在说理性文章中，且多用在分句或句子开头： My mother is by herself; hence I must go home now. 我妈一个人在家，因此我得回去了。 从属连词用法
引导时间状语从句的从属连词
表示“当……时候”或“每当”的时间连词when, while, as, whenever： The phone rang just as I was leaving. 我正要离开，电话铃就响了起来。
2. 表示“在……之前(或之后)”的时间连词before, after： He started the job soon after he left the university. 他大学毕业后就开始做这份工作。
3.表示“自从”或“直到”的时间连词since, until, till： Most men worked until [till] they’re 65. 大多数男人工作到65岁。
4. 表示“一……就”的时间连词as soon as, the moment, the minute, the second, the instant, immediately, directly, instantly, once, no sooner...than, hardly...when等： I went home directly I had finished work. 我一干完活就回家了。
5. 表示“上次”、“下次”、“每次”等的时间连词every 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)： Do look me up next time you’re in London. 你下次到伦敦来，一定来找我。
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 first time中的冠词通常不能省略。 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： If anyone calls tell them I’m not at home.
要是有人打电话来，就说我不在家。
注意：在条件状语从句中，通常要用一般现在时表示将来意义，而不能直接使用将来时态。不过，有时表示条件的 if之后可能用will，但那不是将来时态, 而是表示意愿或委婉的请求(will为情态动词)：
If you will wait a moment, I’ll fetch the money. 请等一下，我就去拿钱。 引导目的状语从句的从属连词
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 that等： We used the computer in order that we might save time. 我们使用计算机是为了节约时间。 引导结果状语从句的从属连词
引导结果状语从句的从属连词主要的有so that, so...that, such...that等： He shut the window with such force that the glass broke. 他关窗户用力很大，结果玻璃震破了。 引导原因状语从句的从属连词
引导原因状语从句的从属连词主要的有because, as, since, seeing (that), now (that), considering (that) 等：
Now that you are here, you’d better stay. 你既然来了，最好还是留下吧。 引导让步状语从句的从属连词
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： Even if you don’t like wine, try a glass of this. 即使你不喜欢喝酒，也尝尝这杯吧。 引导方式状语从句的从属连词
引导方式状语从句的从属连词主要的有as, like, as if, as though, the way等： He behaved as if nothing had happened. 他装作若无其事的样子。 引导地点状语从句的从属连词
引导地点状语从句的从属连词主要的有where, wherever, everywhere等： There were lots of parks where I lived. 我住的地方有许多公园。 引导比较状语从句的从属连词
引导比较状语从句的从属连词主要的有than和as...as： It’s easier than I thought. 这比我想象的要容易。 引导名词性从句的从属连词
引起名词从句的从属连词主要有that, whether, if 等，它们用于引导主语从句、表语从句、宾
语从句和同位语从句。其中that不充当句子成分，没有词义，在句子中只起连接作用；而 if, whether 虽不充当句子成分，但有词义，即表示“是否”。 It is clear enough what he meant. 他是什么意思很清楚。
Your greatest fault is that you are careless. 你最大的缺点是粗心大意。 Whether it will do us harm remains to be seen. 是否对我们有害还要看一看。 She didn’t say if he was still alive. 她没说他是否还活着。 特殊的“从属连词”
1. every time意为“每次，每当”，是一个引导时间状语的从属连词。除了every time外，以下名词性词组如the minute, the moment, the instant, the time, the day, the week, the year, the first time, next time, any time, each time, the last time, from the time, by the time等，都可以作连词用，引导时间状语从句。
I recognized you the minute I saw you. 我一见你就认出了你。 He called on me the day he arrived. 他来的那一天就访问了我。
We were there the week it snowed so heavily. 雪下得很大的那一周我们在那里。 The first time I climbed onto the wall, I felt nervous.我第一次爬到墙上去时，感到胆怯。 Next time you come, you will see the scientist. 你下次来时就会见到那位科学家。 You may come back any time you want to. 你想回来随时可回来。
Each time the tourist traveled by boat he got seasick. 这位旅客每次坐船行时都晕船。 The truck will have arrived by the time you have all the things packed up. 到你把一切东西都捆好时，卡车也就来了。
2. 有些副词如 immediately, directly, instantly 都可以用作连词引导状语从句，相当于as soon as，意为“一……就……”。
You must show the gentleman in immediately he comes. 这位先生一来，你立即引他进来。 There was a dead silence directly he appeared. 他一出现，便鸦雀无声。 It began to rain instantly we arrived home. 我们一到家，天就开始下起雨来。
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