第1个回答 2013-12-30
一.宾语从句的定义
置于动词、介词等词性后面起宾语作用的从句叫宾语从句。宾语从句的语序必须是陈述语序。谓语动词、介词、动词不定式，v.-ing形式后面都能带宾语从句。有些形容词（afraid,sure,glad等）之后也可以带宾语从句。
二.宾语从句中引导词的用法在复合句中作主句的宾语，引导词有：
连词：that (that 常可省略),whether, if
代词：who, whose, what ,which
副词：when ,where, how, why 等。
（一）that引导的宾语从句（在非正式场合that可以省略）
可跟that从句做宾语的动词有：
say, think, insist, wish, hope, demand, imagine, wonder, know, suppose, see, believe, agree, admit, deny, expect, explain, order, command, feel, dream, suggest, hear, mean, notice, prefer, request, require, propose, declare, report等。
例句：The boy believes that he will travel through space to other planets.
注意事项：当主句谓语动词是 think, believe, suppose, expect 等词，而宾语从句的意思是否定时，常把否定转移至主句表示。
例句：I don’t think it is right for him to treat you like that.
在以下情况中that不能省略
当句中的动词后接多于两个由that引导的宾语从句时，第一个that可省，但后面的that不可省。例句：He said (that) you were too young to understand the matter and that he was asked not to tell you.
当主句的谓语动词与that宾语从句之间有插入语时，that一般不可省。例句：Just then I noticed, for the first time, that our master was wearing his fine green coat and his black silk cap.
当that从句是双宾语中的直接宾语时，that不可省。例句：I can’t tell him that his mother died.
注意事项：许多带复合宾语的句子，that引导的宾语从句经常移到句子后部，而用it作形式宾语。
例句：I find it necessary that we should do the homework on time.
（二）由whether,if 引导的宾语从句
由whether(if)引导的宾语从句，实际上是一般疑问句演变而来的。意思是“是否”。宾语从句要用陈述句语序。一般说来，在宾语从句中whether与if可以互换使用，但在特殊情况下if与whether是不能互换的。
例句：I wonder whether(if) they will come to our party.
只能用whether，不能用if引导的宾语从句
在带to的不定式前例句：We decided whether to walk there.
在介词的后面例句：I’m thinking of whether we should go to see the film.
在动词后面的宾语从句时例句：We discussed whether we had a sports meeting next week
直接与or not连用时例句：I can’t say whether or not thet can come on time.
只能用if不能用whether引导的宾语从句
if引导条件状语从句，意为“如果”例句：The students will go on a picnic if it is sunny.
if引导否定概念的宾语从句时例句：He asked if I didn’t come to school yesterday.
引导状语从句even if（即使）和as if（好象）时例句：He talks as if he has known all about it.
（三）连接代词和连接副词引导的宾语从句
这样的宾语从句实际上是由特殊疑问句变化而来的，宾语从句要用陈述句语序。用于这种结构的动词常常是：see, say, tell, ask, answer, know, decide, show, find out, imagine, suggest, doubt, wonder, discover, understand, inform, advise等。
英语中的连接代词有：who,whom,whose,which,what,在句中担任主语、宾语、定语或者表语。
例句：Can you tell me whom you are waiting for?
英语中的连接副词有：when,where,why,how，在句中担任状语的成分。
例句：None of us knows where these new parts can be bought.
三.宾语从句的语序
宾语从句的语序是陈述句语序即：连接代词/副词+主语+谓语+其他成分。例句如下：
I don’t know what they are looking for.
Could you tell me when the train will leave?
Can you imagine what kind of man he is?
四.宾语从句的时态
主句是一般现在时，从句根据实际情况使用任何时态。例句：The headmaster hopes everything goes well.
主句是过去时态，从句须用过去时态的某种形式。例句：She was sorry that she hadn’t finished her work on time.
当宾语从句表示的是一个客观真理或者事实时，即使主句是过去时，从句也用一般现在时态。例句：The teacher told his class that light travels faster than sound.
五.宾语从句的特点
宾语从句可以作及物动词、介词及形容词的宾语。
宾语从句的语序一律用陈述句语序。
连接词that引导宾语从句在句中无词义，不充当句子成份，多数情况下可以省略。
whether 和 if 都可引导宾语从句，但 whether后可紧跟or not；whether从句可作介词的宾语。
如果从句太长，可以用形式宾语it.
引导目的状语从句的连词：inorderthat，sothat（为了）；forfearthat，incase，lest（以免）等。（1）inorderthat，sothat引导的目的状语从句中需用情态动词，现在时态常用may，can或will；过去时态常用could，should或might（含义教正式），有时也用would。inorderthat比so that正式，in order that引导的从句可位于主句前，也可位于主句后；而so that引导的从句只可位于主句后：Hewenttheletterbyairmailinorderthat（或so that）itmightreachthemingoodtime.这封信他航空寄去，以便他们能即使收到。（2）for fear that，in case，lest引导的目的状语从句中常用虚拟语气，从句谓语动词形式常为“should＋动词原形”：Hetookhisraincoatwithhimincase（或for fear that或lest）itshouldrain.他带上了雨衣以免下雨。
不定式作定语的用法不定式及其短语作定语，与其他短语作定语一样，一般都放在被修饰的词之后，通常表示一个将来的动作，有时也可以表示某一过去的特定动作。 一些名词后常用不定式作定语，如：chance(机会），way(方法），time(时间）等；另外，the first,the second,the last,the only等作名词或者它们作形容词用来修饰代词，它们或它们所修饰的代词后，也常用不定式作定语。不定式作定语时，不定式与被修饰词之间存在的关系复杂，有的是主谓关系；有的是动宾关系；有的是动状关系，还有的不存在主谓、动宾、动状关系。1、主谓关系的 （1）We must find a person to do the work. (2) There is no one to take care of her. (3) In my family,my mother is always the first one to get up. (4) He is always the first to come and the last to leave. (5) We need someone to go and get a doctor. 2、动宾关系的 如果不定式与被修饰的词在逻辑上存在动宾关系，不定式里的动词必须是及物动词。注意：是及物动词的，后面不要再加宾语，因为前面的被修饰词是它的宾语；是不及物动词的，要加上适当的介词或副词让它变成及物动词，只有这样，它才能带上前面的宾语。 （1） He has a lot of books to read.(2) I would like a magazine to look at.(3) Here is some advice for you to follow.(4) Do you have anything else to say?(5) There is no one to take care of.(6) She has nothing to worry about.3、动状关系的 被修饰词如果是不定式里动词的状语，应多用介词短语。由于被修饰词前没有介词，所以只能在不定式里的动词后加介词。 （1）Please give me some paper to write on. (2) Let"s find a room to put these things in (3） I have no house to live in. (4) He has no pen to write with. (5) There are five pairs to choose from.4、不存在主谓、动宾、动状关系的 被修饰词与不定式里的动词不存在主谓、动宾、动状关系的，被修饰词多是些抽象名词。 （1）I have no time to go to the movie.（2）There"s no need to send for a doctor. (3) Where"s the best place to meet? (4) Is that the way to do it? (5） I"m not sure about his ability to complete the task alone.
表示目的的状语，常位于句末或句首。常由in order to, so as to, to, in the aim of, to the effct that 引导。
句子的表语是由一个句子充当的,那么这个充当表语的句子就叫做表语从句The fact is that he was cheated.这是个系表结构的句子,the fact是主语,谓语是系表结构,表语是that he was cheated,这个that引导的句子就是表语从句.