省略句定义：为了使语言简洁或避免重复，要省略句中的一个或几个成分，这种语法现象称之为省略。
1，状语从句的省略在when, while, whenever, till, as soon as, if, unless, as if, though 等引导的状语从句中，其实是：包括时间，让步，方式等一些状语从句中，若从句主语和主句主语相同，或者是it时，且从句的主语为be动词时，则从句中的主语和be 动词常全部被省略。
If _______________(heat), water will boil .When ___________(walk) the dog , you were careless and it got loose .常用的一些短语：1, if possible , when/ if necessary, as … as possible, as please (随便)I will do what I can _____________(help) you when necessary.If necessary , I will write him a letter .2, if so (如果是这样)，if ever (如果曾经发生过)，if any(如果有些)，if not (如果不)，even so （即便如此）I will go to the party. If not, I will let you know.I do not like reading popular novels. If any, I can read it.It is likely to rain tomorrow. If so, I will stay at home surfing the Internet.3, 在as, than, however，whatever, no matter what 等引导的从句中，常省略某些成分。
After two hours she became quieter (than she had been). )2，虚拟语气中的省略：1），常省略if，而将had，were, should 提前，构成部分倒装。
__________ he _________(take) my advice, he would have succeeded.2),在suggest动词串中，应用虚拟语气虚拟语气（should +动词原形），should 可省略。
It suggested that we (should ) go to see a film.3，在定语从句和名词性从句中的省略。
1），在限定性定语从句中，常将在从句中做宾语或状语的关系词who, whom, that省略。
The girl _________________ the teacher spoke to is my sister.I don't like the way ________________she speaks to her mother .2), 在know, think, consider等动词后所接的宾语从句中，连词that可以省略，若连接的是两个宾语从句，只有第一个that可以省略，其余的不可以省略。
He said (that) the text was very important and that we should learn it by heart.5, 动词不定式的省略。
1），使役动词let, make, have, 及感官动词see, watch, hear,等后面作宾语补足语的不定式要省去to,但是被动语态要加上toI saw the boy fall from the tree. =>The boy was seen to fall from the tree.The boy wanted to play football in the street, but his mother told him______.A not B not to C not to do D not to do it 2), 有时候为了避免重复，与前文所表达的内容相同的不定式to后面的内容要省略，而只是保持不定式的符号to。
Could you go shopping with me？I am glad to.3), 不定式作某些动词的宾语时，可省略不定式内容，只保留不定式to, 这类动词包括有like, love, hope, wish, expect, refuse, mean, try, agree等You can do it if you mean to.注意：省略的不定式的内容若有作助动词用的have 或be的任何形式时，to 后面的have 或be 要保留。
He did not come, but he ought ________A .toB to haveC ×D to do4), 两个或者两个以上的动词不定式并列在一起由and /or 连接时，第一个不定式待to, 后面的不定式可省略去to，但是表示对比时则不省略to。
Her job is to take care of the children and (to) wash clothes.It is better to laugh than to cry.6, 介词的省略。
1），一些与动词，名词，或形容词一起搭配的介词常省略，而保留其后面的动名词，常见的句型有：have difficulty /trouble (in) doing sth, be busy (in) doing sth, stop / prevent sb (from ) doing sth, waste time (in) doing sth 2) 表示时间的介词at, on 和in 用在next, last, this, these, yesterday, tomorrow, one, any, every, each, some等词之前，一般可以省略。
We go to school every day except (on) Sunday。
In this morning I do morning exercises as usual . (改错）7，在口语中常常出现的省略情况：How come？怎么样会这样呢？表示惊讶。
How so? 为什么？What for? 为什么呢？要求解释原因。
why not? 为什么不呢？表示对意见的赞同。
what？什么？什么事情呢？对对方的话没有听明白时的交际用语。
so what? 那又怎么样？Rick’s parents are a little strange, I think. How so?Would you like to go out for a picnic with us? Why not?8, 用so，not 代替上文提到过的一部分或整个句子Is he coming back tonight? I think so.She must be busy now? If so, she can not go with us.Is she feeling better today? I am afraid not.这种用法常见的有: Why so? Is that so? He said so?注意：肯定式用so代替上文的语义，但否定式用“I don’t suppose/ believe / think / guess so”。
而hope, be afraid, be sure则用“I hope / am afraid / am sure not”。
10 特殊短语中的省略Have nothing to do but doHave no choice but to doDo all / everything what sb can / could (do) to do sthDo as possible as sb can (do) to do sthAt present I have nothing to do but ___________A to waitB waitC waitingD waitedWe will do everything we ____________him when he is in danger .A can doB can to doC can doingD can done省略同步练习：1 _____with the size of the whole earth, the biggest ocean does not seem big at all. (2004湖北高考)A. CompareB. When comparingC. ComparingD. When compared2 That’s an unpleasant thing to say about your father after _______ he’s done for you. (2004高考)A. somethingB. anythingC. allD. that3 A computer does only what thinking people _________.A. have it doB. have it doneC. have done itD. having it done.4 --- Would you like to go to the Great Theatre with me tonight.--- ______.A.Yes, I would like to go to the Great Theater with you tonight .B. I’d love t o, but I have an exam tomorrow.C. No, I wouldn’tD. That’s all right5 --- You haven’t lost the ticket, have you ?--- ______. I know it’s not easy to get another one at the moment.A.I hope notB. Yes, I haveC. I hope soD. Yes, I’m afraid so6 _____ it rain tomorrow, we would have to put off the visit to the Yangpu Bridge.A. WereB. ShouldC. WouldD. Will7 --- Where did you see him last night?---It was in the hotel ____ he stayed.A. whereB. thatC. whichD. /8 (09湖南卷) Every evening after dinner, if not from work, I will spend some time walking my dog.A. being tiredB. tiringC. tiredD. to be tired9 (09江西) Some of you may have finished unit one. _____ , you can go on to unit two.A. If you mayB. If you doC. If notD. If so10 ------shall we have our picnic tomorrow?-----______it doesn’t rain.A. UntilB. WhileC. OnceD. If11 -----Have you got any particular plans for the coming holiday?----- Yes, _______, I’m going to visit some homes for the old in the city.A. If everB. If busyC. If anythingD. If possible12 （2008福建卷，30）– Who should be responsible for the accident?– The boss, not the workers. They just carried out the order _____.A. as toldB. as are toldC. as tellingD. as they told13（2003年上海卷，39）Generally speaking , according to the directions , the drug has no side effect . A．when taking B．when taken C．when to take D．when to be taken14（2004湖北卷，29）What surprised me was not what he said but_______he said it.A. the wayB. in the way thatC. in the wayD. the way which15（2004江苏卷, 28）. -- You haven't lost the ticket, have you?-- _________. I know it's not easy to get another one at the moment.A. I hope notB. Yes, I haveC. I hope soD. Yes, I’m afraid so16（2005全国卷, 21）--–Can I speak to Mr Wang, please?--________.A. Who are you ?B. I’m WangC. SpeakingD. Are you Zhang17（2005重庆, 27）__________, he talks a lot about his favorite singers after class.A. A quiet student as he may beB. Quiet student as he may beC. Be a quiet student as he mayD. Quiet as he may be a student18（2005福建，33）When_______help, one often says “Thank you.” or “It’s kind of you”.A. offeringB. to offerC. to be offeredD. offered19（2006年湖北，29）-- I was wondering if we could go skiing on the weekend.-- _______good.A. SoundB. SoundedC. SoundingD. Sounds20（2006年湖北，31）__________ fired, your health care and other benefits will not be immediately cut off.A. Would you beB. Should you beC. Could you beD. Might you be21 ______as it is，it can understand you.A dog B. Dog C. Dogs D. The dog22 —What should I do with this passage?—______the main idea of each paragraph.(2005重庆卷)A. Finding outB. Found outC. Find outD. To find out23“What made her so happy?”“______her son passed driving test.”A. ThatB. 不填C. SinceD. For24 ——What made her so happy?——_____________.A Pass the examB To pass the examC Passing the examD Passed the exam25 Boris has brains. In fact，I doubt whether anyone in the class has ______ IQ.A. a highB. a higherC. the higherD. the highestKeys : DCABA BACDD DABAA CBDDB BCACB。