1、should 和ought to 都为应该的意思，可用于各种人称。-Ought he to go?-Yes. I think he ought to.表示要求，命令时，语气由 should（应该）、had better最好）、must（必须）渐强。1) 动词+ 不定式 afford aim appearagree arrangeaskbe decidebothercarechoose come dare demanddesiredetermine expectelectendeavorhopefail happen helphesitatelearn longmean manage offer
2、 ought planpreparepretend promiserefuseseem tend wait wish undertake举例： The driver failed to see the other car in time. 司机没能及时看见另一辆车。I happen to know the answer to your question. 我碰巧知道你那道问题的答案。2）动词+不定式 ；动词+宾语+不定式ask, beg, choose, expect , hate, help intend like, love, need prefer, prepare, promise,
3、want, wishI like to keep everything tidy.我喜欢每件东西都保持整洁。I like you to keep everything tidy.我喜欢你年使每件东西都保持整洁。I want to speak to Tom. 我想和汤姆谈话。I want you to speak to Tom. 我想让你和汤姆谈话。不定式作补语1) 动词+宾语+不定式(to do)advise allow believe cause challengecommandconsiderenableencourage findguess hireimagineinvite know
4、likeorder permitpersuade remind reportrequest requireselectsend tell thinktrust understandurge warn例句： a.Father will not allow us to play on the street. 父亲不让我们在街上玩耍。 b.We believe him to be guilty. 我们相信他是有罪的。Find 的特殊用法： Find 后可用分词做宾补，或先加形式宾语，再加形容词，最后加带to 的动词不定式。find后也可带一个从句。此类动词还有get，have。I found him
5、 lying on the ground. I found it important to learn. I found that to learn English is important.典型例题:The next morning she found the man _ in bed，dead. A. lying B. lie C. lay D. laying答案：A.find的宾语后面，用分词或分词短语，起宾语补足语作用。现在分词表达主动，也表达正在进行，过去分词表达被动。2) to + be 的不定式结构，作补语的动词。believe,consider,think,declare(声称
6、),discover,feel find,guess,imagine,know, prove, understand We consider Tom to be one of the best students in our class. 我们认为汤姆是班上最好的学生之一。典型例题 Charles Babbage is generally considered_ the first computer.A. to inventB. inventing C. to have invented D. having invented 答案：A. 由consider to do sth. 排除B、D。.
7、 此句只说明发明这一个事实，不定式后用原形即可。而C为现在完成时，发明为点动词一般不用完成时，且此处也不强调对现在的影响，因此不选C。不定式主语1） Its easy (for me) to do that.我做这事太容易了easy,difficult, hard, important, possible, impossible,comfortable, necessary, better;the first, the next,the last,the best,too much,too little,not enoughIts so nice to hear your voice.听到你的
8、声音真高兴。Its necessary for you to lock the car when you do not use it.当你不用车的时候，锁车是有必要的。2) Its very kind of you to help us.他帮助我们，他真好。Kind,nice, stupid,rude, clever,foolish,thoughtful,thoughtless,brave,considerate(考虑周到的),silly, selfish(自私的)例句:It was silly of us to believe him.我们真愚蠢，竟然相信了他。It seemed selfi
9、sh of him not to give them anything.他不给他们任何东西，这显得太自私了。注意：1) 其他系动词如，look，appear等也可用于此句型2) 不定式作为句子成分时，动词用单数形式。3) 当不定式作主语的句子中又有一个不定式作表语时，不能用It is to的句型(对)To see is to believe.百闻不如一见。(错)It is to believe to see.Its for sb.和 Its of sb.1）for sb. 常用于表示事物的特征特点，表示客观形式的形容词，如easy, hard, difficult, interesting,
10、impossible等： Its very hard for him to study two languages. 对他来说学两门外语是很难的。 2）of sb的句型一般用表示人物的性格，品德，表示主观感情或态度的形容词，如good, kind, nice, clever, foolish, right。 Its very nice of you to help me. 你来帮助我，你真是太好了。*for 与of 的辨别方法：用介词后面的代词作主语，用介词前边的形容词作表语，造个句子。如果道理上通顺用of，不通则用for。如： You are nice.(通顺，所以应用of)。 He is
11、hard.(人是困难的，不通，因此应用for。)2）作宾语a. 动词后加动名词doing作宾语 V. + doing sthadmit 承认appreciate 感激,赞赏avoid 避免complete 完成 consider 认为deny 否认 endure 忍受enjoy 喜欢prevent阻止 finish 完成 imagine 想象 mind 介意miss 想念postpone 推迟practise 训练resist 抵抗 resume 继续risk 冒险 suggest 建议face 面对understand 理解 forgive 宽恕keep 继续举例：(1)Would you
12、mind turning down your radio a little, please? (2)The squirrel was lucky that it just missed being caught.b. 词组后接doing admit to prefertobe used to习惯于lead todevote oneself tostick to busylook forward to(to为介词） no good,no use,Its worth, as well as, cant help,Its no use /good be tired of be fond of be
13、capable of be afraid of be proud of think of / aboutput off keep on insist on be successful in good attake upgive upburst outprevent from3）作表语Her job is washing，cleaning and taking care of the children.动名词与不定式1） 动名词与不定式的区别：动名词表达的是： 状态，性质，心境，抽象，经常性，已发生的不定式表达的是： 目的，结果，原因，具体，一次性，将发生的2） 接不定式或动名词，意义相同。 3
14、） 动名词与不定式语义不同的有11 组： 1stop to dostop doing 2 forget to do forget doing 3remember to doremember doing 4 regret to do regret doing 5cease to do cease doing 6 try to dotry doing 7go on to do go on doing 8 afraid to do afraid doing 9interested to dointerested doing 10 mean to do mean doing11 begin/ star
15、t to do begin/ start doingstop doing/to dostop to do停止，中断做某事后去做另一件事。stop doing停止做某事。They stop to smoke a cigarette. 他们停下来，抽了根烟。I must stop smoking. 我必须戒烟了。典型例题 She reached the top of the hill and stopped _on a big rock by the side of the path.A. to have restedB. resting C. to restD. rest答案：C。由题意可知，她
16、到了山顶，停下来在一个路边的大石头上休息。因此，应选择stop to do sth. 停下来去做另一件事。而不仅仅是爬山动作的终止，所以stop doing sth.不正确。forget doing/to doforget to do忘记要去做某事。(未做)forget doing忘记做过某事。(已做)The light in the office is stil on. He forgot to turn it off.办公室的灯还在亮着，它忘记关了。(没有做关灯的动作)He forgot turning the light off. 他忘记他已经关了灯了。 ( 已做过关灯的动作)Dont
17、forget to come tomorrow.别忘了明天来。 (to come动作未做)典型例题- The light in the office is still on.- Oh，I forgot_. A. turning it off B. turn it off C. to turn it off D. having turned it off 答案：C。由the light is still on 可知灯亮着，即关灯的动作没有发生，因此用forget to do sth.而forget doing sth表示灯已经关上了，而自己忘记了这一事实。此处不符合题意。remember doi
18、ng/to doremember to do 记得去做某事 (未做)remember doing记得做过某事 (已做)Remember to go to the post office after school.记着放学后去趟邮局。Dont you remember seeing the man before? 你不记得以前见过那个人吗?regret doing/to doregret to do 对要做的事遗憾。(未做)regret doing 对做过的事遗憾、后悔。(已做)I regret to have to do this, but I have no choice.我很遗憾必须这样去
19、做，我实在没有办法。I dont regret telling her what I thought.我不为告诉她我的想法而后悔。典型例题-You were brave enough to raise objections at the meeting. -Well, now I regret _ that.A. to do B. to be doing C.to have done D.having done答案：D。regret having done sth. 对已发生的事感到遗憾。regret to do sth. 对将要做的事感到遗憾。本题为对已说的话感到后悔，因此选D。try do
20、ing/to dotry to do努力，企图做某事。try doing 试验，试着做某事。You must try to be more careful.你可要多加小心。I tried gardening but didnt succeed.我试着种果木花卉，但未成功。go on doing/to dogo on to do做了一件事后，接着做另一件事。go on doing 继续做原来做的事。 After he had finished his maths，he went on to do his physics. 做完数学后，他接着去做物理。 Go on doing the other
21、exercise after you have finished this one. 作完这个练习后，接着做其他的练习be afraid doing/to dobe afraid to do不敢，胆怯去做某事，是主观上的原因不去做，意为怕；be afraid of doing担心出现doing的状况、结果。 doing 是客观上造成的，意为生怕，恐怕。She was afraid to step further in grass because she was afraid of being bitten by a snake.她生怕被蛇咬着，而不敢在草丛中再走一步。She was afrai
22、d to wake her husband.她不敢去叫醒她丈夫。She was afraid of waking her husband.她生怕吵醒她丈夫。be interested doing/to dointerested to do 对做某事感兴趣，想了解某事。interested in doing 对某种想法感兴趣，doing 通常为想法。I shall be interested to know what happens.我很想知道发生了什么事。 (想了解)Im interested in working in Switzerland. Do you have any idea ab
23、out that?我对在瑞士工作感兴趣。你想过这事吗? (一种想法)mean to doing/to domean to do 打算、想mean doing意味着I mean to go, but my father would not allow me to.我想去，但是我父亲不肯让我去。To raise wage means increasing purchasing power.赠加工资意味着增加购买力。begin(start) doing/to dobegin / start to do sth begin / start doing sth.1)谈及一项长期活动或开始一种习惯时，使用
24、doing. How old were you when you first started playing the piano? 你几岁时开始弹钢琴？2)begin, start用进行时时，后面动词用不定式to doI was beginning to get angry。我开始生起气来。3)在attempt, intend, begin, start 后接know, understand, realize这类动词时，常用不定式to do。 I begin to understand the truth。我开始明白真相。4)物作主语时It began to melt.感官动词 + doing
25、/to do感官动词 see, watch, observe, notice, look at, hear, listen to, smell, taste, feel + do 表示动作的完整性，真实性；+doing 表示动作的连续性，进行性I saw him work in the garden yesterday.昨天我看见他在花园里干活了。(强调我看见了这个事实)I saw him working in the garden yesterday.（强调我见他正干活这个动作）昨天我见他正在花园里干活。典型例题1）They knew her very well. They had seen
26、 her _ up from childhood. A. grow B. grew C. was growing D. to grow 答案：A。因题意为，他们看着她长大，因此强调的是成长的过程，而非正在长的动作，因此用see sb do sth 的句型。2）The missing boy was last seen _ near the river.A. playing B. to be playingC. playD. to play答案A. 本题强调其动作，正在河边玩，应此用see sb. doing sth句型。比较过去时与现在完成时 1）过去时表示过去某时发生的动作或单纯叙述过去的事
27、情，强调动作；现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。 2）过去时常与具体的时间状语连用，而现在完成时通常与模糊的时间状语连用，或无时间状语。一般过去时的时间状语:yesterday, last week，ago, in1980, in October, just now, 具体的时间状语共同的时间状语:this morning, tonight,this April, now, once，before, already, recently，lately现在完成时的时间状语for, since, so far, ever, never, just, yet,till
28、/ until, up to now, in past years, always,不确定的时间状语 3）现在完成时可表示持续到现在的动作或状态，动词一般是延续性的，如live, teach, learn, work, study, know. 过去时常用的非持续性动词有come, go, leave, start, die, finish, become, get married等。举例： I saw this film yesterday.（强调看的动作发生过了。） I have seen this film. （强调对现在的影响，电影的内容已经知道了。） Why did you get
29、up so early?（强调起床的动作已发生过了。） Who hasnt handed in his paper?（强调有卷子，可能为不公平竞争。） She has returned from Paris. 她已从巴黎回来了。 She returned yesterday. 她是昨天回来了。 He has been in the League for three years.(在团内的状态可延续) He has been a League member for three years.(是团员的状态可持续) He joined the League three years ago. ( 三年
30、前入团，joined为短暂行为。) I have finished my homework now. -Will somebody go and get Dr. White? -Hes already been sent for. 句子中如有过去时的时间副词（如 yesterday, last, week, in 1960）时，不能使用现在完成时，要用过去时。 （错）Tom has written a letter to his parents last night. （对）Tom wrote a letter to his parents last night.用于现在完成时的句型1）It
31、is the first / second time. that结构中的从句部分，用现在完成时。 It is the first time that I have visited the city. It was the third time that the boy had been late.2）This is the that结构，that 从句要用现在完成时. This is the best film that Ive (ever) seen. 这是我看过的最好的电影。 This is the first time (that) Ive heard him sing.这是我第一次听他
32、唱歌。典型例题(1) -Do you know our town at all? -No, this is the first time I _ here.A. was B. have been C. came D. am coming 答案B. This is the first time 后面所加从句应为现在完成时，故选B。(2) -Have you _ been to our town before? -No, its the first time I _ here.A. even, come B. even, have comeC. ever, come D. ever, have c
33、ome 答案D. ever意为曾经或无论何时，反意词为never，此两词常用于完成时。 This is the largest fish I have ever seen. It is / was the first time +that-clause 的句型中，从句要用完成时。 注意：非延续性动词的否定形式可以与表示延续时间的状语连用。即动作不发生的状态是可以持续的。（错）I have received his letter for a month.（对）I havent received his letter for almost a month.比较since和forSince 用来说明
34、动作起始时间，for用来说明动作延续时间长度。I have lived here for more than twenty years.I have lived here since I was born.My aunt has worked in a clinic since 1949. Some new oilfields have been opened up since 1976. I have known Xiao Li since she was a little girl. My brother has been in the Youth League for two years
35、.I have not heard from my uncle for a long time.注意：并非有for 作为时间状语的句子都用现在完成时。 I worked here for more than twenty years. (我现在已不在这里工作。) I have worked here for many years. (现在我仍在这里工作。)小窍门：当现在完成时+一段时间，这一结构中，我们用下面的公式转化，很容易就能排除非延续动词在完成时中的误使。1)(对) Tom has studied Russian for three years. = Tom began to study
36、 Russian three years ago, and is still studying it now.2)(错) Harry has got married for six years. = Harry began to get married six years ago, and is still getting married now.显然，第二句不对，它应改为 Harry got married six years ago.或 Harry has been married for six years.since的四种用法1) since +过去一个时间点(如具体的年、月、日期、钟
37、点、1980, last month, half past six)。 I have been here since 1989. 2) since +一段时间+ ago I have been here since five months ago. 3) since +从句 Great changes have taken place since you left. Considerable time has elapsed since we have been here. 4) It is +一段时间+ since从句 It is two years since I became a pos
38、tgraduate student.延续动词与瞬间动词1) 用于完成时的区别延续动词表示经验、经历； 瞬间动词表示行为的结 果，不能与表示段的时间状语连用。 He has completed the work.他已完成了那项工作。 (表结果) Ive known him since then. 我从那时起就认识他了。(表经历)2)用于till / until从句的差异 延续动词用于肯定句，表示做直到 瞬间动词用于否定句，表示到，才 He didnt come back until ten oclock. 他到10 点才回来。 He slept until ten oclock. 他一直睡到10
39、点。典型例题1. You dont need to describe her. I _ her several times.A. had metB. have met C. metD. meet 答案B. 首先本题后句强调对现在的影响，我知道她的模样，你不用描述。再次，several times告知为反复发生的动作，因此用现在完成时。2.-Im sorry to keep you waiting.-Oh, not at all. I _ here only a few minutes.A. have been B. had been C. wasD. will be 答案A. 等待的动作由过去
40、开始，持续到现在，应用现在完成时。和more有关的词组1) the more the more越就越 The harder you work，the greater progress youll make.2) more B than A与其说A不如说B less A than B He is more lazy than slow at his work.= He is less slow than lazy at his work.3) no more than 与一样，不比多 The officials could see no more than the Emperor.no less
41、 than与一样He is no less diligent than you.4) more than不只是，非常She is more than kind to us all.典型例题1）The weather in China is different from_.A. in America B. one in America C. America D. that in America 答案：D. 本题意为中国的天气比美国热。比较的是天气而不是国家，C不能选。A没有名词，后句成分不全，排除。B和D中，B中的one常用来代替可数名词，而that可车以代替不可数或抽象名词，所以选D。2）Af
42、ter the new technique was introduced，the factory produced _ tractors in 1988 as the year before. A. as twice manyB. as many twiceC. twice as manyD. twice many as 答案C. 此句意为这个厂1988能生产的拖拉机是往年的两倍。 表示倍数用倍数+ as + 形容词原形+ as +比较对象的句型。所以此句答案为C。This ruler is three times as long as that one.as + 形容词或副词原级 + as1
43、）在否定句或疑问句中可用so as。He cannot run so/as fast as you.2）当as as 中间有名词时采用以下格式。 as +形容词+ a +单数名词 as + many/much +名词 This is as good an example as the other is. I can carry as much paper as you can.3）用表示倍数的词或其他程度副词做修饰语时，放在as的前面。This room is twice as big as that one.Your room is the same size as mine.4) 倍数+
44、as + adj. + as 倍数+ then + ofThis bridge is three times as long as that one.This bridge is three times the length of that one.Your room is twice as large as mine.Your room is twice the size of mine.比较级形容词或副词 + than You are taller than I. They lights in your room are as bright as those in mine.注意： 1）要避免重复使用比较级。 (错) He is more cleverer than his b
