英语从句

一：从句概说 从句是相对于主句而言的，即它是从属于某一个主句，而不能单独作一个句子。在 英语 关于好奇心的名言警句英语高中英语词汇下载高中英语词汇 下载英语衡水体下载小学英语关于形容词和副词的题 中，主要有三大类从句，即名词性从句（包括主语从句，宾语从句， 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 语从句，同位语从句）、形容词性从句（即定语从句）、副词性从句（即状语从句, 包括时间、条件、结果、目的、原因、让步、地点、方式等）。 1. 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。 2. 宾语从句用作宾语。如： Do you know where he lives? 3. 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。 4. 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） 5. 定语从句相当于一个形容词，用于修饰前面的名词或代词。如： The student who answered the question was John. 回答问题的学生是John. 6. 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） 二：名词性从句 主语从句、宾语从句、表语从句、同位语从句在复合句中起名词的作用，所以这四种从句合称名词性从句。它们在主句中充当主语、宾语、表语、同位语，都不能用逗号与主句分开。 名词性从句的三要素 1.​ 引导词 　 引导名词性从句的引导词可分为三类： 　　(1) 连词： that （无任何词意） 　　 whether, if （均表示“是否”表明从句内容的不确定性） 　　 as if ,as though （均表示“好像”，“似乎”） 　　 以上在从句中均不充当任何成分 (2) 连接代词： what, whatever, who, whoever, whom, whomever, which, whichever ,whose 　　(3) 连接副词： when, where, how, why 既然是引导词，所以这些词就总是位于名词性从句的最前面。 (1). 连词 that 只起连接作用，没有任何意思，也不充当句子成分，在宾语从句中可省略，但引导其他名词性从句时通常不省略。如： I hope (that) you enjoy your holiday. 希望你假期过得好。 That he likes you is very obvious. 很显然他喜欢你。 (2). 连词 whether 也不充当句子成分，但有自己的意思，表示“是否”：引导宾语从句时，可换成 if，但引导其他名词性从句时不能换成 if。如： He asked whether [if] I would show him the way. 他问我是否可以给他带路。 Whether it will do us harm remains to be seen. 是否对我们有害还要看一看。(引导主语从句，不能用 if 代替 whether) (3). 连接代词 who(m), whose, which, what 等，均有各自的意义，在从句中作主语、宾语、定语等。如： Tell me which one you like best. 告诉我你最喜欢哪一个。 (4). 连接副词 when, where, how, why 等，也各自有自己的意义，在从句中作状语。如： The question is how we should carry out the plan. 问题是怎样执行这个 计划 项目进度计划表范例计划下载计划下载计划下载课程教学计划下载 。 When she’ll be back depends much on the weather. 她什么时候回来在很大程度上要看天气。 Why he did it will remain a puzzle forever. 他为什么这样做将永远是一个谜。 名词性从句的重要引导词 (1). what 用于引导名词性从句是一个十分重要的引导词，它可引导主语从句、宾语从句和表语从句，但不用于引导同位语从句。它引导的名词性从句有两个意思是：一是表示“ 什么”，带有疑问意味；二是表示“…所…的”，相当于一个先行词后接一个关系代词。如： I don’t know what you want. 我不知道你想要什么。 I don’t know what you want is this. 我不知道你所想要的是这个。 (2). what 引导名词性从句时可用作限定词，其后修饰名词。如： I gave him what books I had. 我把我所有的书都给他了。 He gave me what money he had about him. 他把身边带有的钱全给了我。 注：what 后的名词可以是复数名词或不可数名词，但通常不能是单数可数名词，并且后接不可数名词时，有时可有little修饰，两者的区别是：what+不可数名词=所有的都，what little+不可数名词=虽少但全部。如： What friends she has are out of the country. 她有的那些朋友全在国外。 We gave him what (little) help we could. 我们给了他我们力所能及的帮助。 (3). whoever, whatever, whichever 等也可引导名词性从句，其意分别为“所…的一切事或东西”、“任何…的人”、““…的任何人或物”等。如： Whoever wants the book may have it. 任何人要这书都可拿去。 I’ll do whatever I can to help him. 我们将尽我们所能来挽救他。 Buy whichever is cheapest. 买最便宜的。 不可省略的连词： 　　1. 介词后的连词 　　2. 引导主语从句和同位语从句的连词不可省略。 　　 That she was chosen made us very happy. 　　 We heard the news that our team had won. 　　whether与if 均为"是否"的意思。 但在下列情况下，whether 不能被if 取代： 　　1. whether引导主语从句并在句首 　　2. 引导表语从句 　　3. whether从句作介词宾语 　　4. 从句后有"or not" 　　Whether he will come is not clear. 　　大部分连接词引导的主语从句都可以置于句末，用 it充当形式主语。 　　It is not important who will go. 　　It is still unknown which team will win the match. 2. 语序 名词性从句都必须与陈述句语序相同，即“主语＋谓语”。事实上，任何一种从句，其语序都必须与陈述句的语序相同。 名词性从句的词序与陈述句语序相同，尤其注意那些由连接代词who(m), whose, which, what 和连接副词 when, where, how, why 等引导的名词性从句，不要受它们在特殊疑问句中用法的影响而误用疑问句词序。如： Why was she crying? 她为什么在哭？ I don’t know why she was crying. 我不知道她为什么哭。 3. 时态 若主句的谓语动词是一般现在时时，宾语从句的谓语动词可根据情况使用各种时态；若主句的谓语动词是一般过去时，宾语从句若不是一个客观事实或真理，其谓语动词也必须用某种过去时态。 (1). 当主句的谓语动词是过去式时，宾语从句若不是一个客观事实或真理，其谓语动词也必须用某种过去时态。如： She said (that) she didn't want to know. 她说她不想知道。 I asked her whether she would agree. 我问她是否会同意。 (2). when, if 这两个词既可引导名词性从句，也可引导状语从句。当它们引导名词性从句且表示将来意义时，要直接使用将来时态；但当它们引导状语从句且表示将来意义时，则必须用一般现在时表示将来意义。如： I don’t know when he will come, but when he comes, I’ll call you. 我不知道他什么时候，但当他来的时候，我会打电话给你。 句中第一个when 引导的是宾语从句，故用将来时态表示将来意义；第二个when 引导的是时间状语从句，故用一般现在时表示将来意义。 (一)：主语从句 1、​ 定义：在复合句中作主语的从句叫做主语从句。 主语从句通常由连词that，whether，if和连接代词what，who，which，whatever，whoever以及连接副词when，where，how，why等词引导。that在从句中无词义，只起连接作用；连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，并在从句中充当成分。例如： What he wants to tell us is not clear. 他要跟我们说什么，还不清楚。 Who will win the match is still unknown. 谁能赢得这场比赛还不得而知。 It is known to us how he became a writer. 我们都知道他是如何成为一名作家的。 Where the English evening will be held has not yet been announced. 英语晚会将在 哪里举行，还没有宣布。 Why he left wasn't important. (wasn't是主句的谓语动词，why he left做主语从句) That she became an artist may have been due to her father's influence. (may have been due是主句的谓语动词，that she became an artist做主语从句) 2、​ 借助形式主语it，主语从句放在后面 有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下： 　　（1） It + be + 名词 + that从句 　　（2） It + be + 形容词 + that从句 　　（3） It + be + 动词的过去分词 + that从句 　　（4） It + 不及物动词 + that 从句 　　另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should) +do”，常用的句型有： 　　It is necessary (important, natural, strange, etc.) that … 　　It is a pity (a shame, no wonder, etc.) that… 　　It is suggested (requested, proposed, desired, etc.) that… 主语从句常放在句尾而用 it 作形式主语使句子更加平衡，这时口语中常省略 that, 如上面第一句改成“It is evident (that) mathematics finds its use in every science.”更好。 在下列情况下必须把主语从句放在句尾而用 it 作形式主语： 1． 主句谓语是被动语态时，如： It is said that he is a good doctor. 2． 主句是疑问句或感叹句时，如： Is it true that the film star will come? How wonderful it is that we'll visit the Great Wall tomorrow. 3． 主句谓语动词是 appear, turn out, happen, occur, come, strike, follow, matter 等时，如： It happened that she had a cold and didn't go with us that day. It turned out that I was wrong. 4． 表示说话人的推测或评价，如在 it seems, it may be, it is (un)likely, it is (im)possible, it is a pity, it is a wonder 等结构中，如： It seems that this test is reliable. It is a pity (that) she can't go with us. 5． 强调主句的表语时，如： It is a mystery to me how it all happened. It is necessary that he should do so. wh-疑问词引导的主语从句，可以放在句首(第一组)，也可以借助形式主语it(第二组)。 第一组：When he'll be back depends much on the weather. How it was done was a mystery. Whether we'll succeed remains to be seen. 第二组：It is uncertain whether the game will be held. It's a puzzle how life began. It doesn't matter much where we live. Is it known where he went？ （二）：宾语从句 1、定义：在复合句中作宾语的从句叫做宾语从句。 第一组：I guess(that) we'll leave soon. He asked when we would be in London. She informed me (that) she was to send for it the next day.(that可以省略) I'll tell you what I read in today's paper. 第二组：I'll find out whether she's interested in going. Can you give us a description of what has happened. She was shocked by what she had seen. 2、借助形式宾语it，that引导的宾语从句放在后面。 I've heard it said that you have won a scholarship. 分析：it在句中做形式宾语，said做宾语补足语，that you have won a scholarship是真正的宾语。 She has seen to it that all the children are well taken care of. 分析：it在句中做形式宾语，that all the children are well taken care of是真正的宾语。 在宾语从句中须注意： (1). that 在口语中常被省略，但在正式的文体中，不能省；并且它一般不能引导介词的宾语从句，但可引导except, but, in 等少数介词的宾语从句。如： I didn’t know (that) he was Li Lei. 我不知道他就是李蕾。 I will do anything I can to help you except that I’m ill. 只要我身体舒服，我愿做任何事情来帮助你。 (2). 宾语从句之后带有补足语成分时，一般须用it作形式宾语，把宾语从句放到句末，此时的that不能省。如： The boy has made it clear that they can’t play with his toys. 那个男孩已清楚的表明他们不能玩弄他的玩具。 (3). 动词advise, ask, demand, desire, insist(坚决主张), order, propose, request, suggest(建议)等代的宾语从句须用虚拟语气，即：(should) do的形式。 He asked that we (should) get there before nine o’clock. 他要求我们在九点钟之前赶到那儿。 The teacher advised us that we (should) not waste our time. 老师劝告我们不要浪费时间了。 (4). 宾语从句的时态与主句的时态须呼应。即： 1)当主句谓语动词的时态是现在时或将来时，从句的谓语动词可用任何所需要的时态表示。如： He always says that he is our good friend. 他总是说他是我们的好朋友。 When the teacher knows what we have done, he will say that we have done a good deed. 当老师知道我们所干的事情时，他会说我们做了一件好事。 2)当主句谓语动词的时态为过去时，从句的谓语动词须用响应的过去时。如： He didn’t tell us he came from Shanghai. 他没有告诉我们他来自上海。 He said he had read the book. 他说他读过这本书。 3)但当从句的内容是客观真理或客观事实，而不受时间的限制时，即使主句谓语动词为过去时，从句仍用一般现在时。如： Chairman Mao said that all the imperialists are paper tigers. 毛主席说一切帝国主义者都是纸老虎。 When we were children, we were told that China is in the east of the world. 我们还是小孩子的时候，人们就告诉我们说中国在世界的东方。 八种宾语从句不省略that 引导宾语从句的that在下列情况下一般不省略： 1. 宾语从句前有插入语。如： We hope, on the contrary, that he will stay at home with us. 恰恰相反，我们希望他和我们呆在家里。 2. 有间接宾语时。如： He told me that he was leaving for Japan. 他告诉我他要去日本。 3. that在与之并列的另一个宾语从句之后。如： He said (that) the book was very interesting and that(不省略) all the children like to read it.他说那本书很有趣，所有小孩都喜欢读。 4. 在“it(形式宾语)+补语”之后时。如： I think it necessary that he should stay here. 我们认为他有必要留在这里。 5. that从句单独回答问题时。如： —What did he hear? 他听说了什么事？ —That Kate had passed the exam. (他听说)凯特考试及格了。 6. 在except等介词后。如： He has no special fault except that he smokes too much.他除了抽烟太多之外,没有什么特别的毛病。 7. 位于句首时。如： That our team will win, I believe. 我相信我们队会赢。 8. 在较为正式或不常用的动词(如reply, object)后。如： He replied that he disagreed. 他回答说他不同意。 （三）：表语从句 1、定义：在复合句中作表语的从句叫表语从句。表语从句位于连系动词后，有时用as if引导。其基本结构为：主语 + 系动词 + that从句。例如： 　　The fact is that we have lost the game. 事实是我们已经输了这场比赛。 　　That’s just what I want. 这正是我想要的。 　　This is where our problem lies. 这就是我们的问题所在。 　　That is why he didn’t come to the meeting. 那就是他为什么不到会的原因。 　　It looks as if it is going to rain. 看上去天要下雨了。 表语从句中应注意： 1. 连接词that一般不能省略，但当主句中含动词do的某种形式时，that可以省略。如： What I want to do is (that) I can go up to him and thank him. 我想做的事是走到身边去感谢他。 2. 当句子的主语是：advice, demand, decision, desire, idea, insistence, instruction, order, plan, proposal, recommendation, request, requirement, suggestion, wish等名词时，表语从句须用虚拟语气，即：should +do。如： My advice is that you should go to apologize to him. 我的建议是你应该去向他道歉。 3．当主语是reason时，表语从句要用that引导而不是because。例如： The reason why he was late was that he missed the train by one minute this morning . 4．whether 可引导表语从句，但与之同义的if却通常不用于引导表语从句。 （四）：同位语从句 1、定义：有些名词的后面可以跟that引导的从句，说明这个名词的内容，这样的从句叫做同位语从句。所以，只有可以有内容的名词才可以接同位语从句，例如：fact，message，idea，possibility，conclusion，thought，news，order，report，rumor等等。that在从句中不做成分，但是不能省略。 例： He had the feeling that he would not see her again. I've come to the conclusion that it won't be wise to do so. 表示“命令、建议、要求” advice, demand, decision, desire, idea, insistence, instruction, order, plan, proposal, recommendation, request, requirement, suggestion, wish 等名词的同位语，须用虚拟语气。如： He made clear his desire that he should work hard to go to college. 他已清楚的表明了他要努力学习考上大学这一愿望。 Soon came the order that all the people should obey the rules. 不久命令下来了， 所有的人不得违犯 制度 关于办公室下班关闭电源制度矿山事故隐患举报和奖励制度制度下载人事管理制度doc盘点制度下载 。 2、有时为了保持句子的平衡，同位语从句有时和前面的名词分开。 The rumor spread that a new school would be built here. that引导的同位语从句修饰the rumor，但是主句The rumor spread太短，如果把后面的同位语从句放在the rumor后面，主语太长，给人头重脚轻的感觉。 3、在少数情况下，名词性从句的其他关联词也可以引导同位语从句。但if不可以引导同位语从句。 You have no idea how worried I was. I have no idea why she left. There is some doubt whether John will come on time. 4. 同位语从句与定语从句的区别： 同位语从句与定语从句形相似而实质不同，具体表现在以下几个方面： (1) 被修饰的词不同。同位语从句的前面一般是数量有限的、表示抽象意义的名词；而定语从句的先行词是无数的指人或指物名词。 (2) 从句的作用不同。同位语从句表示同位名词的具体内容；而定语从句是对先行词—名词的限制、描绘或说明。 (3) 引导词的作用不同。引导同位语从句的that是连词，在从句中不担任任何成分，但不能省略；而引导定语从句的that为关系代词，在从句中担任句子的某种成分，当担任定语从句中的宾语时，that可以省略。 (4) 引导词不同。定语从句不能用what, how, whether引导；而同位从句可以用what, how, whether引导。 在学习名词性从句时注意下面四点： 一、名词性从句要用陈述语序，也就是说：①名词性从句的关联词在从句中做主语的话，关联词后面接谓语动词；②名词性从句的关联词在从句中不做主语的话，关联词后面接从句的主语和谓语。 ① I don't know who broke the window.(宾语从句中关联词who做主语，broke是谓语动词) ② The little boy told his mother where he found the coin.(宾语从句中关联词where不做主语，where后面接主谓部分he found) 二、感叹句做名词性从句时语序不做变化 Don't you know how excited I was then？ 三、时态的呼应 某些从句(特别是宾语从句)中的动词时态，常受主句谓语时态的制约。 ① 如果主句谓语动词为现在时或将来时，从句中的谓语可以不受影响。例如： Has he told you when he received the gift？ Will you tell me how you two are getting along？ ② 如果主语谓语动词为过去时，从句谓语一般要跟着改为相关的过去时。 I didn't know where they lived.He thought he was working for the people.asked him how long he had been waiting. ③ 但是，当宾语从句表示永恒真理时谓语可以不变：This proved that the earth is round. 四、当and连接两个that引导的宾语从句时，and后面的that不可以省略 She promised (that) she would come and see him sometimes and that she would never forget him.句中的第一个that可以省略，为了清楚地表示出第二个that引导的是宾语从句，第二个that不省略。 （五）：名词性that-从句 　　1）由从属连词that引导的从句叫做名词性that-从句。 That只起连接主句和从句的作用，在从句中不担任任何成分，本身也没有词义。名词性that-从句在句中能充当主语、宾语、表语、同位语和形容词宾语，例如： 　　主语：That she is still alive is her luck.　他还活着全靠运气。 　　宾语：John said that he was leaving for London on Wednesday.　约翰说他星期三要到伦敦去。 　　表语：The fact is that he has not been seen recently.　事实是近来谁也没有见他。 　　同位语：The fact that he has not been seen recently disturbs everyone in his office. 近来谁也没有见过他，这一事实令办公室所有的人不安。 　　形容词宾语：I am glad that you are satisfied with your job. 你对工作满意我感到很高兴。 　　2）That-从句作主语通常用it作先行词，而将that-从句置于句末，例如： It is quite clear that the whole project is doomed to failure.　很清楚，整个计划注定 要失败。 It's a pity that you should have to leave.　你非走不可真是件憾事。 用it作形式主语的that-从句有以下四种不同的搭配关系： 　　a . It + be +形容词+ that-从句 　　 It is necessary that…　有必要…… 　　 It is important that…　重要的是…… 　　 It is obvious that…　很明显…… 　　b . It + be + -ed 分词+ that-从句 　　 It is believed that…　人们相信…… 　　 It is known to all that…　众所周知…… 　　 It has been decided that…　已决定…… 　　c . It + be +名词+ that-从句 　　 It is common knowledge that…　……是常识 　 　It is a surprise that…　令人惊奇的是…… 　 　It is a fact that…　事实是…… 　　d . It +不及物动词+ that-从句 　 　It appears that…　似乎…… 　 　It happens that…　碰巧…… 　　 It occurred to me that…　我突然想起…… （六）：名词性wh-从句 　　1）由wh-词引导的名词从句叫做名词性wh-从句。Wh-词包括who, whom,. whose, whoever, what, whatever, which, whichever等连接代词和when, where, how, why等连接副词。Wh-从句的语法功能除了和that-从句一样外，还可充当介词宾语、宾语补语和间接宾语等，例如： 　　主语： How the book will sell depends on its author.　书销售如何取决于作者本人。 　　直接宾语：In one's own home one can do what one likes.　在自己家里可以随心所欲。 　　间接宾语：The club will give whoever wins a prize.　俱乐部将给得胜者设奖。 　　表语： My question is who will take over president of the Foundation.　我的问题是谁将接任该基金会主席职位。 　　宾语补足语：She will name him whatever she wants to. 她高兴给他起什么名字就取什么名字。 　　同位语：　I have no idea when he will return.　　我不知道他什么时候回来。 　 形容词宾语： I'm not sure why she refused their invitation.　我尚不能肯定她为什么拒绝他们的邀请。 　　介词宾语：　That depends on where we shall go.　那取决于我们去哪儿。　 　　2）Wh-从句作主语也常用先行词it做形式主语，而将wh-从句置于句末，例如： 　　It is not yet decided who will do that job.　还没决定谁做这项工作。 　　It remains unknown when they are going to get married.　他们何时结婚依然不明。 （七）：if, whether引导的名词从句 　　1）yes-no型疑问从句 　　从属连词if, whether引导的名词从句是由一般疑问句或选择疑问转化而来的，因此也分别被称为yes-no型疑问句从句和选择型疑问从句，其功能和wh-从句的功能相同， 例如： 　　主语： Whether the plan is feasible remains to be proved. 这一计划是否可行还有等证实。 　　宾语： Let us know whether / if you can finish the article before Friday.　请让我们知道你是否能在星期五以前把文章写完。 　　表语： The point is whether we should lend him the money.　问题在于我们是否应该借钱给他。 　 同位语：They are investigating the question whether the man is trustworthy.　他们调查他是否值得信赖。 　　形容词宾语： She's doubtful whether we shall be able to come.　她怀疑我们是否能够前来。 　　介词宾语： I worry about whether he can pass through the crisis of his illness.　我担心他是否能度过疾病的危险期。　 2）选择性疑问从句 　　选择性疑问从句由关联词if/whether…or或whether…or not构成，例如： Please tell me whether / if they are Swedish or Danish. 请告诉我他们是瑞典人还是丹麦人。 　　I don't care whether you like the plan or not.我不在乎你是否喜欢该计划。 　　if和whether的区别： 　　1、 在动词不定式之前只能用whether 。如： 　　 I can’t decide whether to stay. 我不能决定是否留下。 　　2、 在whether …… or not 的固定搭配中。如： 　　 I want to know whether it’s good news or not . 我想知道是否是好消息。 　　3 、在介词后，只能用whether。如： His father is worried about whether he lose his work . 他的父亲担心是否会失去工作。 　　4、宾语从句放在句首表示强调时，只能用whether 。如： 　　 Whether this is true or not, I really don’t know. 这是否真的，我真的不知道。 　　5、用if会引起歧义时，只用whether。如： 　　 Could you tell me if you know the answer ? 　　 这句话有两种意思：“你能告诉我是否知道 答案 八年级地理上册填图题岩土工程勘察试题省略号的作用及举例应急救援安全知识车间5s试题及答案 吗？”或“如果你知道答案，请告诉我，好吗？”。如用whether可避免歧义. （八）：否定转移 　　1) 将think, believe, suppose, expect, fancy, imagine等动词后面宾语从句的否定词转移到主句中，即主句的谓语动词用否定式，而从句的谓语动词用肯定式。 　　I don't think I know you.　我想我并不认识你。 　　I don' t believe he will come.　我相信他不回来。 　　注意：若谓语动词为hope,宾语从句中的否定词不能转移。 　　I hope you weren't ill. 我想你没有生病吧。 2) 将seem, appear 等后的从句的否定转移到前面。 　　It doesn't seem that they know where to go. 　　看来他们不知道往哪去。 　　It doesn't appear that we'll have a sunny day tomorrow. 　　看来我们明天不会碰上好天气。 3) 有时将动名词，介词短语或整个从句的否定转变为对谓语动词的否定。 　　I don't remember having ever seen such a man.　 　　我记得从未见过这样一个人。 (not否定动名词短语 having…) 　　It's not a place where anyone would expect to see strange characters on the street. 　　在这里，人们不会想到在街上会碰上陌生的人。 　　(anyone 作主语，从句中的谓语动词不能用否定形式。)　 4) 有时状语或状语从句中否定可以转移到谓语动词前。 　　The ant is not gathering this for itself alone.　(否定状语)　蚂蚁不只是为自己采食。 　　He was not ready to believe something just because Aristotle said so. (否定because状语) 他并不因亚里斯多德说过如何如何，就轻信此事。 　　She had not been married many weeks when that man's younger brother saw her and was struck by her beauty.　(否定状语many weeks)　她结婚还不到几个月，这个人的弟弟就看见她了，并对她的美貌着了迷。 英语名词性从句的特点 英语的名词性从句（Noun clause）具有名词的句法功能，在句子中充当主语、宾语、表语和同位语。其表现特点有以下六个方面： 1．来源于疑问句并含间接疑问的名词性从句。例如： How the prisoner escaped remains a mystery.（主语从句） 试比较：How did the prisoner escape? I wonder whether/if he is fit for the job.（宾语从句） 试比较：Is he fit for the job? The problem is who will be equal to the task.（表语从句） 试比较：Who will be equal to the task? He had no idea whether we could overcome the present difficulties or not.（同位语从句） 试比较：He asked whether/if we could overcome the present difficulties. 引导此类名词性从句的连接词直接来源于疑问句的疑问词。名词性从句用陈述句语序。 2．来源于陈述句的名词性从句。例如： That he came back made us very happy.（主语从句） 试比较：He came back. I’m sorry (that) I’ve made a mistake.（宾语从句） 试比较：I’ve made a mistake. He pretended (that) he didn’t see me.（宾语从句） 试比较：He didn’t see me. The fact is that his bark is worse than his bite.（表语从句） 试比较：His bark is worse than his bite. Word came that he would come to see us all.（同位语从句） 试比较：He would come to see us all. 由此可见，凡由陈述演绎而来的名词性从句，其引导词一律为that。引导宾语从句的that在口语或非正式语体中常可省略。 3．来源于“先行词+定语从句”的名词性从句，其引导词一般是含有先行词在内的关系代词“what”。例如： What the teacher says has a deep effect on his pupils.（主语从句） 试比较：All (that)the teacher says has a deep effect on his pupils. The doctor did what he could to save the dying boy.（宾语从句） 试比较：The doctor did everything (that)he could to save the dying boy. China is no longer what she used to be.（表语从句） 试比较：China is no longer the country that she used to be. 4．来清于“any+定语从句”的强调式名词性从句，其引导词为whoever, whomever, whatever, whichever等。例如： Whoever breaks the law is to be punished.（主语从句） 试比较：Anyone who breaks the law is to be punished. He will give the dictionary to whoever needs if most.（宾语从句） 试比较：He will give the dictionary to anyone who needs it most. We’ll remember whomever we turned to for help. 试比较：We’ll remember anyone (whom) we turned to for help. They will do whatever he wants them to do.（宾语从句） 试比较：They will do anything that he wants them to do. I’ll read whichever book you give me.（宾语从句） 试比较：I’ll read any of the books that you give me. Whoever comes first may have enough to do.（主语从句） 试比较：Anyone who comes first may have enough to do. 5．来源于感叹句的名词性从句，其引导词是what和how。例如： Margaret told him what a good deed he had done.（宾语从句） 试比较：What a good deed you have done! George, you don’t know how hard it is to make both ends meet.（宾语从句） 试比较：How hard it is to make both ends meet! 感叹句充当名词性从句仍具有感慨的意思。 6．名词性从句与非谓语动词之间存在转换关系。名词性从句取代原句的非谓语动词部分仍可在句中作主语、宾语、表语或同位语，基本意思不变。例如： 1 . That she lost her necklace on the way home made her so worried. Losing her necklace on the way home made her so worried. 2 . We suggested that he be sent to hospital at once. We suggested his (him) being sent to hospital at once. 3 . No one noticed that some boys were playing under the bridge. No one noticed some boys playing under the bridge. 4 . It is necessary that we should learn a second language. It is necessary for us to learn a second language. 5 . She didn’t know whether she should go or stay. She didn’t know whether to go or to stay. 6 . It is said that he works hard at English. He is said to work hard at English. 7 . It (so) happened that I had read the book. I happened to have read the book. 8 . It seems that they are talking about something over there. They seem to be talking about something over there. 三：定语从句 一：有关定语从句的概念 (1)定语从句：就是在复合句里充当定语的从句，它通常紧靠在所修饰的名词或代词（先行词）后面。 (2)先行词：就是定语从句所修饰的名词或代词。 (3)关系词：引导定语从句的词叫关系词。 关系词有关系代词who, whom, whose, which和that等；关系副词有when, where, why等。关系词不仅起连接作用，而且还代表先行词并在定语从句中担任某一句子成分，关系代词在从句中作主语、宾语、表语、定语等; 关系副词在从句中作状语。 如： This is the book that my father bought me yesterday. 这就是我父亲昨天帮我买的那本书。 说明：句中修饰the book的that my father bought me yesterday就是定语从句；被定语从句所修饰的the book这是先行词；代表the book的关系代词that在定语从句中作bought的直接宾语。 The time when he arrives is not known. 他到达的时间还不知道。 说明：句中when he arrives是定语从句，被定语从句修饰的the time是先行词，关系副词when作时间状语。 二：定语从句的结构：关系词+主语+谓语+其他 三：关系词的选择 (1). 一看先行词的意义，即分清先行词是指人、指物、时间、地点还是原因，如指物时不能用who或whom，指人时通常不用which等。 A plane is a machine that can fly. 飞机是一种能飞行的机器。(that指物，在从句中用作主