-学年新人教版高一英语语法讲解专题优化教案设计必修1+++5连词 五、连词连词是虚词，不能在句中单独担任成分，只起连接作用按其用法，连词可分为两大类：并列连词和从属连词1并列连词连接具有并列关系的词、短语或句子⒈并列关系：and，not only…but also…，both…and…，neither…nor…如：I used to live in Paris and London.Both Jane and Jim are interested in fishing.The weather here is neither too cold nor too hot.She is not only kind but also honest.⒉转折关系：but，yet，while（然而），when（然而，偏偏）如：The car is very old but it runs very fast.The problem was a little hard,yet I was able to work it out.The winter in Beijing is very cold while that of Kunming is warm.Why did you borrow the book when you had one?⒊选择关系：or，not…but…，either…or…如：Would you like to live or would you like to stay?He is not a teacher but a writer.You can come either on Saturday or on Sunday.⒋因果关系：for如：It must have rained last night,for the ground is wet now.The leaves of the trees are falling. for already autumn.5. 区别①and和or⑴并列结构中，or通常用于否定句，and 用于肯定句。
⑵但有时and 也可用于否定句请注意其不同特点：如：There is no air or water in the moon.There is no air and no water on the moon.在否定中并列结构用or连接，但含有两个否定词的句子实际被看作是肯定结构，因此要用and判断改错：（错)We will die without air and water.（错）We cait live without air or water.（对）We will die without air or water.（对)We cant live without air and water.②表示选择的并列结构⑴or意思为“否则"I must work hard,or I will fail in the exam.⑵either，or 意思为”或者……或者……注意谓语动词采用就近原则Either you or I am right.③表示转折或对比⑴but表示转折，while表示对比Some people love cats,while others hate them.⑵not…but…意思为“不是……而是……"not和but后面的用词要遵循一致原则。
They were not the bones of an animal,but(the bones) of a human being.③表原因关系⑴for是并列连词，不能置于含两个并列分句的句子的句首，只能将其放在两个分句中间判断改错：（错）For he is ill,he is absent today.（对）He is absent today,for he is ill.④so,therefore如：He hurt his leg, so he coudn’t lplay in the game.注意：a. 两个并列连词不能连用，但therefore，then，yet可以和并列连词连用You can watch TV, and /or you can go to bed.b.although，yet 但although不能与but连用⑤注意：not only，but also 关联两个分句时，一个分句因有否定词not而必须倒装如：Not only does he like reading stories,but also he can even write some.neither…nor…意思为“既不……也不……“谓语动词采用就近原则，与nor后的词保持一致。
⑥比较so和such其规律由so与such的不同词性决定such 是形容词，修饰名词或名词词组，so是副词，只能修饰形容词或副词so还可与表示数量的形容词many，few，much，little连用，形成固定搭配⑴so many 已成固定搭配，a lot of虽相当于many，但a lot of为名词性的，只能用such搭配⑵so，that与such，that之间的转换即为so与such之间的转换2从属连词指在复合句中引导从句的连结词⒈常见的从属连词有：引导时间状语从句的：after，before，when，as，while，since，until，till，as soon as引导原因状语从句的：because，since，as引导让步状语从句的：although，though，no matter（无论），even if (though)引导条件状语从句的：if，unless，once，as (so) long as引导结果状语从句的：so，so that，so…that…，such…that…引导目的状语从句的：so，so that…，in order that…引导比较状语从句的：as…as，not so (as)，as，than引导方式状语从句的：as，as if…，as though引导地点状语从句的：where，wherever引导名词性从句（主语，宾语、表语或同位语从句）的连词主要有：that，whether，if三个。
其中that和whether间或还可以引起同位从句和状语从句⒉某些用法比较特殊的从属连词用法区别①当while,when,as引导时间状语从句时的区别：⑴while引导的状语从句中动词必须是延续性谓语动词多为进行时，或状态动词的一般时while的这些用法可用when代替，等于“at the time that",“during the time that”如：Please keep quiet while(when)others are studying⑵when除可指一段时间外，还可用来指一点时间，等于“at the time；when引出的时间状语从句中的谓语动词可以是终止性的，也可以是延续性的因此主句和从句的谓语可以是一般时，进行时，或完成时如：When I went into the lab,the teacher was doing an experiment.（不能用while)He often makes mistakes when he is speaking English （then 可换成while)⑶as 常可与when，while通用，但强调“一边、一边”如：As(when/while) I was walking down the street, I noticed a police car in front of number 37.⑷when 引导的状语从句中的主语与主句主语一致，主、谓是“主语+系动词”结构时，这时主语和系动词可以省略。
如：When (he was)young. he worked for a rich man.She'll be here to give you help when (if it is)necessary.⑸when有时代替if，引导条件句，意为“如果”“假如”如：I'll come when (if）I'm free.②before作连词一般表示时间，意为“在.…之前”，但有些句子中这样译就显得别扭试看以下句子的翻译：He almost knocked me down before he saw.他且乎把我撞倒才看见我；Before I could get in a word he had measure.没来得及插话，他已经给我量好了尺寸③till,until作为介词式从属连词，只用于时间，引导时间状语短语或状语从句，用于否定句时，结构为not…until(till)主句谓语动词延续与非延续皆可，意为“直到……才……”用于肯定句时，只与延续性动词连用，表示“到……为止”如：They played volleyball until(till)it got dark.They didn't talk(延续）until(till) the interpreter（译员）came.He didn't go to bed（非延续）until(till) the his father came back但是，until可以放在句首，till则不行。
如：Until the last minute of the match we kept on playing.Not until he finished his work did he go home.（倒装）④because,since,as引导原因状语时注意使用上的区别：⑴如果原因构成句子的最主要部分，一般用because 因此because引导的从句往往放在句末用why提问的句子，一定用because 回答如：He had to stay at home yesterday because he was ill.⑵如原因已为人们所知，或不如句子的其他部分重要，就用as，或sincesince比as更正式些as和since引导的从句一般放在句子的开头如：As you are tired,you had better rest/Since everyone is here,now let's begin.⑤although和though 引导让步状语从句往往用法一样，但注意以下区别：⑴although 用于各种文体，而though则多用于非正式的口语或书面语中注意由although,though 引导的从句后，主句不能用but，但可用副词yet，still。
如：Although/Though it rained all the morming, they still went on work或yet they went on working.⑵though 常与even连用，even though表示强调，意为“即使”，但不能说even although如：Even though he didn't understand a word,I dept smiling.⑶though可用作副词，意为“然而”，常用逗号与句子分开lthough 则不能这样使用，它只作连词如：It was a quiet party,I had a good time though.。