英语三大从句
主语从句用作主语，如：： That the earth is round is true. 地球为圆的是真实的。 宾语从句用作宾语。如： Do you know where he lives 表语从句用作表语，如： My opinion is that you should not go alone. 我的意见是你不应单独前往。 同位语从句用于解释说明前面的名词。如： The fact that the earth is round is true. 地球是圆的的事实是真实的。（that从句用于解释说明the fact） 定语从句相当于一个形容词，用于修饰前面的名词。如： The student who answered the question was John. 回答问题的学生是John. 状语从句相当于一个副词，如： When it rains, I usually go to school by bus. 天下雨时，我通常坐公共汽车上学。（时间状语） If he comes tomorrow, you will e him. 如果他明天来，你就可以看见他。（if 引导的条件状语从句，其结构为：if +状语从句，＋主句）。要注意在状语从句中有一个规则是“主将从现”，即主句是将来时，则从句要用一般现在时表示将来。 主句和从句的划分方法是相同的。句子的成分从谓语动词处来划分比较容易。谓语动词前面的部分是主语，后面常接宾语，修饰谓语动词的是状语，修饰主语、宾语的是定语，若谓语是系动词，则系动词后的部分是表语。如： I am a teacher. 其中，I 是主语，am是谓语，a teacher 是表语。 He likes playing football very mucy. 其中，he是主语，likes是谓语，playing football是宾语，ver
y much是状语。 名词性从句 名词性从句有四类：宾语从句、主语从句、表语从句、同位语从句。例如： 宾语从句：I don’t know where he will go. 主语从句：Where he will go is unknown. 表语从句：The problem is how we can get so much money. 同位语从句：We all feel sorry about the news that he failed in the game. 下面几点是学习名词从句要加以注意的： 1． whether和if都可以引导宾语从句表达“是否”意，（即引导宾语从句时if和whether 可以互换）但以下几种名词从句要用whether（不用if）引导： （1） 引导主语从句，且在句首时。例：Whether he has won the tennis is not known.(但 It is not known whether/if he has won the tennis). （2） 引导表语从句时。例The problem is whether he can get a job. （3） 引导同位语从句时。例：I have no idea whether he will come. （4） 介词后的whether从句。例：I worry about whether I hurt her feelings. 2． 位于句首引导主语从句的that不可忘。 例如：That he got the first place in the competition surprid all of us. 3． 在“It is suggested/propod/ordered/a pity/no wonder/necessary/strange/…＋ that从句”结构中，that从句谓语有时用（should）do这样的虚拟语气形式。 例如：It is suggested that we(should) improve the relations between us. It is a pity that one(should) stay in one place all one´s life. It is strange that she should have failed to e her own sh
ortcomings（缺点）. 4． 在“The reason why…is that…”句式中that不要误为becau. 例如：The reason why he didn´t go to school yesterday is that he was ill. 5． 名词从句中that,what用法比较： 引导名词从句的that是连词，在句中无成份，无意义，而what是连接代词，what＝the thing(s) that. 例如：It was told in yesterday´s newspaper that what the students had done was praid by the factory. I know that he will study. I know what he will study. That he works hard at his lessons is known to us all. What he works hard at is known to us all. All I ask is that you should tell the truth./He is not what(＝the person that)he ud to be.他和以前大不相同了。 6． where在名词从句中的使用特点： where在名词从句中有时可以变为“the place where”,有时可以变为“介词＋the place where” 形式。例如： 主从：Where(＝The place where)she has gone is still unknown. 宾从：Would you plea tell me where(＝the place where) Mr Smith lives 表从：Your dictionary remains where(＝in/at the place where)you put. 同位从：Have you any idea where(＝of the place where) she is spending her holidays 7． 无论是哪种名词从句都是陈述语序。例如： I know where he lives./Plea tell me what her name is. 当一个特殊疑问句本身就是陈述语序（即“主＋谓＋（宾）”或“主＋系＋表”结构），将其变为间接引语（即宾语从句）时，无
需改变语序。例如： What´s the matter with him She asked me what was the matter with him. Who looks after your grandfather He asked me who looked after my grandfather. 形容词性从句定语从句 一、 定语从句与引导词 定语从句是在复合句中修饰某一名词或代词的从句。被修饰的名词或代词叫做选行词， 而引导定语从句的词叫引导词，有关系代词和关系副词两类。 懂得什么样的先行词后用什么样的引导词是学好定语从句的关键。 1． 关系代词有：that,which,who,whom,who,在定语从句中作主语、宾语中表语，who 作定语。代人的有：who,whom,who,that；代物的有：that,which,who.例如： The man who helped you is Mr White.(who代人，在定语从句中作主语) That is the person(whom/who/that) you want to e.(whom,who,that代人，在定 语从句中作宾语，可省略) I´m not the fool(that) you thought me to be.(that代人，在定从中作表语) A dictionary is a uful book which(＝that) tells us the meaning of words(which 或that代物，在定从中作主语) 2． 关系副词有：when(指时间)，where(指地点),why(指原因)，在定语从句中作状语。 例如：Would you suggest a time(when) we can have a talk(when可省略) The hou where they live is not very large./This is the reason why he did not came to the meeting. 注意：不是表时间的先行词都用when引导定从，不是表地点的先行词都用where
电脑虚拟内存怎么设置
引导定从。例如：We´ll visit the factory which(＝that) makes radios. (which或that在定从中作主语，where不可用主语，故不可用) They still remember the happy days(which/that) they spent in Beidaihe. (which或that在定从中作spent的宾语，when不可作宾语，故不可用) 二、限制性定语从句与非限制性定语从句 限制性定语从句和主句之间不用逗号分开，修饰主句中的某一个名词或名词词组或代 词；非限制性定语从句常用逗号和主句隔开，可以修饰主句中的某一个词，也可修饰整个句子。非限制性定语从句不能用that引导，引导非限制性定语从句的关系词不能省略。非限制性定语从句例：Li Ping´s father, who works in a factory, is an engineer./He tore up my photo, which made me very angry.(which指代主句内容，因前后两句是因果关系，此时which不可换为as。) He is good at physics, as is known to us all.＝As is known to us all, he is good at physics.(as指代主句内容，在as is known/believed, as we all know/believe这类结构中as不可换为which) 三、 只用that引导和不用that引导的场合 1． 只用that引导和不用that引导的场合 1） 当先行词既包括人又包括物时：He talked about the men and the books that attracted him. 2） 指物的先行词被any, every, only, very, all, no等修饰时：The are the very points that interest me./That´s the only watch that I like most. 3） 指物的先行词被序数词或形容词最高级修饰时：The fir
st step that we are to take is very difficult./This is the cond card that he gave me. 4） 先行词是指物的不定代词 all, little , few ,wate much,及everything , anything , nothing等时：There is still much that can be done about it./Have you got everything that you need 5） 先行词是who时：Who that have en him does not like him 2． 不用that的场合如下： 1）非限制性定语从句中 Last night ,I saw a very good film ,which was about the Long March . 2）介词放在关系代词之前时 This is the man from whom I learnt the news 3）句中出现了that，或先行词是that时 I have found that which I was looking for.
副词性从句 状语从句 时间状语从句： When Susan goes to town, she will visit her grandma.. 苏珊每次进程，总要去看望她奶奶。
地点状语从句： I will go where I am needed. 哪里需要我，我就到哪里去。
方式状语从句： I have changed it as you suggest. 我已经按照你的建议作了改变。
原因状语从句： Mary didn’t go shopping becau I advid her not to. 玛丽没有去购物，因为我劝她不要去。
目的状语从句： They worked hard in order that they might succeed. 他们努力工作，以便能够获得成功。
结果状语从句： Waste must be treated so that it does not become a danger to life. 废物必须进行处理，这样它才不会成为危害生命的东西。
条件状语从句： If he works hard, he will surely succeed. 如果努力工作，他肯定会成功。
让步状语从句： Though we are all different, we need never be parate.
比较状语从句： I was happier than I had ever been in my life. 这是我一生中最快乐的时光。
时间状语从句： (1) 时间状语从句由下列连词引导：After, as, before, once, since, till, until, when, whenever, while, as soon as ) Let's wait till the rain stops. 咱们等到雨停再说吧。 Once the train is moving, there's no way to stop it.火车一旦开动就没办法让它停下来。 They were scolded whenever they were late for school. 每次他们上学迟到都挨骂。 （2）有一些表示时间的名词短语也可用来引导时间状语从句：The minute, the moment, every time, the first time） The moment he reached the country, he started his arch. 他一到达这个国家，就开始他的探寻工作。 Every time I saw the straw hat, it reminded me of the tour I made years before. 每当我看到那顶草帽，它就使我想起几年前的那次旅游。 I thought her nice and honest the first time I met her。我第一次见到她就觉得她诚实而友善。 （3）有一些表示时间的副词也可用来引导时间状语从句：风味绝佳 Directly the master came in, everyone was quiet. 校长一进来， 大家就安静下来。 The young lady rushed into the room immediately she heard the noi. 那位年轻女士一听到响声就冲进房间。
（4）as的用法 1）．某事一发生，另一事立即发生 As the sun ro the frog disperd. 太阳一出来雾就消散。 They strolled into the garden as the music cead. 音乐声一停，他们就走进花园。 2）．在某事发生的过程中另一事发生 香酥鸡蛋灌饼I heard the murmur of their voices as I crosd the hall. 我走过大厅的时候听到他们在嘀咕什么。（两个动作都是一般时态） Just as he was speaking there was a loud explosion. 正当他在说话的时候，一声巨响。（从句用进行时态） 3）．两个动作同时发生 He smiled as he pasd. 他路过的时候笑了一下。（两个都是短暂动作） As she sang, the tears ran down her cheeks. 她一边唱歌，眼泪一边从脸颊淌下。 Helen heard the story as she washed. 海伦一边洗衣服一边听故事。 He saw that she was smiling as she read. 他看到她一边看着书一边笑。（两个都是延续性动作） We get wir as we get older. 我们随着年龄的增长而变得聪明起来。（随着时间的变化而变化） （5硬件是什么）when的用法：
1）．以when引导的时间状语从句中，既可用短暂性动作也可用延续性动作。I bought the car when I received my first salary.（短暂性动作）我是在领第一笔薪水的时候买的车。 Don't get excited when you talk.（延续性动作）说话的时候不要激动。 2)．when 容易与时间状语从句混淆的例子(请注意：此项中when引导的都不是时间状语从句。) She had just finished dressing when her guests came in. 她刚刚穿戴完毕，这时她的客人进来了。 (这里的when不是从属连词，而是并列连词。所以它引导的是并列句。像这类问题有以下主要特征) when 后面的分句动词必须是瞬间动词，用于表示突然性： We were about to start when it began to rain.正当我们要出发的时候，突然下雨了。 3）.when 前面的分句是过去进行时： He was still smiling when the door opened and his wife came in. 他正笑着，突然门开了，他的妻子走了进来。 4）.when 前面的分句含有be about to, be on the point of: He was on the point of leaving when someone knocked at the door. 他正要出发的
时候，突然有人敲门。 5）.when 前面的分句采用过去完成时或是过去完成进行时： We had just fallen asleep when the telephone rang. 我们刚刚入睡，突然电话铃声响了。 The plane had been planting ed for nearly a month when it began to rain. 飞机播种了近一个月，这时天才下雨。 (6)．while的用法 （以while引导的时间状语从句中，只能用延续性动作。） They arrived while I was sunbathing. 当我正在进行日光浴时，他们来了。 While the discussion was still going on, Mr. Zhang came in. 当讨论还在进行的时候，张先生进来了。
原因状语从句 becau, as, since, 用来引导原因状语从句。for虽然也是表示原因，但是它不是从属连词，而是并列连词。 (1) becau 表示最强的因果关系，表达听话者未知的原因，becau引导的从句通常放在后面，表示强调时也可放在前面。becau引导的从句可以用来回答Why引起的特殊疑问句。He got the job becau he was the best candidate. 他得到那份工作，因为他是最佳人选。 “Why can’t I go” 吃老虎的兔纸“Becau you are too young.” 为什么我不能去因为你年纪太小。 （2）as 所表示的原因通常是听话者已经知道的。因而它不是句子
的中心。不能用来回答Why引起的特殊疑问句。 As all the ats were full, he stood up. 由于所有的座位都满了，他只好站着。 鸟鸣涧古诗的意思Perhaps she’ll need some help, especially as she’s been ill.惠州大学是几本 她可能需要帮助，尤其是因为她一直有病。 （3）since所表示的原因通常也是听话者已经知道的。同样since也不能用来回答Why引起的特殊疑问句。 Since you are going, I will go too. 既然你要去，我也去吧。 （4）for 从语法分析的角度来说，它不是引导状语从句，而是构成一个并列句。 for 通常用于书面语，它通常不表示因果关系，而是对前面的分句进行补充说明。for-分句通常放在句末，for 之前有逗号。 He laughed little, for he was a sad man. 他很少发笑，因为他是个多愁的人。 She was clearly upt, for her eyes were filled with tears. 她显然心烦意乱，因为她眼眶里饱含泪水。
