英语语法（05动词b）

Unit Five: Auxiliary, Infinitive, Participle（II） Issues of this unit: 1) Auxiliary verbs 助动词 2) Verb infinitives 动词不定式 3) Participles of -ed and -ing 分词,英语中一共有3个基本助动词：do, have, be和13个情态动词（modal verbs）（Page 281）。 do 作助动词：加在否定词前构成否定句(do not) 可以加在主动词前表示强调 Do be honest! I do want it! have 作助动词：主要协助构成完成体等 have done be 作助动词：主要协助构成进行体、被动态等 be doing be done,1) Auxiliary verbs 助动词,这里我们关注的是情态动词，它们分别表示能力、可能、必然、义务、许可、意愿、决心等。 Most likely, you are already experts on what they mean. For instance: I believe I can fly. / You can use my car. We ought to abide by the traffic rules. It must have rained, cause the ground is wet. The truth will out.,所以，接下来我们看看一些需要注意的问题。 1. can and be able to: 由于can没有多少形态变化，所以表示能力时一般表示现在的能力，而过去和将来的能力一般用be able to(时态的区别)。could虽然也可指过去的能力，但一般不指具体能力。 I can speak English = Im able to speak English. CAFUC students will be able to win the CCTV CUP. The genius could (was able to) write at age 4. But: Schumacher was able to drive the racing car when he was a child.,还有：can可以表示机会、条件等，able to则不能。 Every child can dream of becoming the president. She can go to university not because she studies well, but because she dances well. 注1：在否定句中，cannot = not be able to; couldnt = was (were) not able to; could即可指一般能力，也可表示具体能力. We couldnt (werent able to) reach the summit of the mountain because of the storm. 注2：can表示“许可”时不能用be able to替换；如： You can always use my typewriter. You are always able to use my typewriter. ,3. 那么need的否定是什么？ 作动词：-Do the students need to submit their term paper before Friday? -Not necessarily/No, they dont need to. 作助动词：You neednt make two copies. One will do. Need we come tomorrow? 而may not的含义为“也许不”，例如： Is he really right? He may not be right.,4. Dare 的用法： 1） dare用作实义动词，此时其后的动词不定式可带to也可不带to。 I dare to jump down from the top of the wall. She doesnt dare (to) meet her teachers eyes. 2） dare用作情态动词，主要用于疑问句、否定句和条件句中。 How dare she do things like that to me? Dare you catch the mouse? -I darent do that.,5. 情态动词不定式进行或完成体, 表示推测或可能性： They may (might) be leaving tomorrow morning. He may have missed the train. You couldnt have met sister Mary. She died before you were born. Its so late, and he cant be still working. Since the ditch is full of water，it must have rained last night. 表示与设想相反的事态： She should have let me know it sooner. I might have helped her some. I have never expected that the pickpocket should have returned my purse! It is really a tragedy that the Yangtse River dolphin should have been extinct.,6. can， could， may， might都可以表示可能性 can， could表示潜在的可能性或理论上或逻辑判断上存在的可能性；而may， might则表示事实上的可能性。此外，can还具有“有能力”的意思，而may与might则不具此意。例如： According to the weather forecast， it may rain tomorrow. Any man with a little sense can see that he is wrong.,1) 1) The phone is ringing,_(但是没人接听。她一定不在家) 2) I cant find my sunglasses. I may have left them in the coffee shop yesterday _(我可能昨天落在咖啡店里了). 3) You screamed in your sleep last night. you must have dreamed of something terrible _(你一定梦见什么可怕的东西了). 4) Its a pity. You should have invited her to your graduation ceremony _(你本应该邀请她来参加你的毕业典礼的). 5) I neednt have put on my best suit to go to the party _(其实我没必要穿上我最好的套装去参加那次聚会的); most of the guests were wearing jeans and sweaters.,2) Verb infinitives 动词不定式,1. to+动词原形的时、体、态： We still a long way to go in learning English. That night owl is said to be sleeping at lunch time. The rescue team was too late to come and the victims were found to have died. The traffic accident is reported to have been caused again by drunk driving. 2. 不定式一般带有to，但也有不带to的场合： （Pages 325-329） Go get my beer !,下面这些动词前需要加 “to”吗: 1. God said: “Let there _ be light! And there is light.” 2. Wed rather _ die on our feet than _ live on our knees! 3. We cannot but _ marvel at humans landing on the moon. 4. I could do nothing but _ wait 5. You had better _ do your job well, or you get fired. 6. Sorry that you have to make _ do with the poor living conditions here.,7. The neighbors see her _ sleepwalk almost every night. 8. She is seen _ sleepwalk almost every night by the neighbors. 9. Its important to rely on ourselves rather than _ wait for help from others. 10. Rather than _ risk breaking up his marriage he told his wife everything. 11. Everybody says Id make a great engineer but what I really want to do is _ write 12. We mustnt let _ slip such an opportunity.,3. “to”后面动词的省略 You may go on daydreaming, if you want to. Im not being perfunctory. I never want to be. They have not found anything as they expected to have. 4. 区分不定式“to”与介词“to”；(pp.334-338) I look forward to hearing from you. The boy swears to love the girl all his life. The boy swears to having witness a UFO. The swimmer used to warm up before a match. The swimmer was used to warming up before a match.,Some exercises: 1. Im not accustomed to (burn) midnights oil. 2. I came near to (tell) him the whole truth, but then thought better of it. 3. In police department, the boy witnessed to (have) seen the drunken driver of the BMW. 4. He was the only one who objected to (resume) the journey right away. 5. Finally, the candidate resigned to (lose) the campaign. 6. What the teacher has said is the key to (do) the experiment.,5. 不定式与形容词、名词、动词搭配使用 These are what you have already learned. The structures are usually: be + adj. + to do sth. be + NP + to do sth. VP + to do sth. e.g.: Dogs are easy to keep as pets. This is my first time to teach English grammar. I consider all of you to be honest students.,6. “to”的一个特例： A human being, in the true sense of the word, should eat to live, but not live to eat. The Red Army arrived at the Jinshajiang River, only to find that there was no boat on it. to do表示目的；only to do却表示结果。,1.没有钱的时候，人都努力为金山银山而奋斗；真的有了很多钱，却觉得还不如挣一个吃一个的时候幸福。 With an empty pocket, one strives for an ocean of wealth, but he has his pocket full, only to find that hes no happier than the time when he lives from hand to mouth.,2. 纳粹法西斯曾试图征服世界，到头来却 以惨败而告终。 The Nazi fascists attempted to conquer the world, only to end up in fiasco.,3. 我们都想追求完美，结果发现世界上没有最好，只有更好。 We all endeavor to be perfect, only to realize that there is only something better, and nothing the best.,4. 他很自私，不愿为孤儿们做任何事情。 It was selfish of him not to do anything for the orphans.,4. 她做了这么多牺牲是为了送她的孩子进大学。 She has sacrificed so much in order to send her kid to the unicersity.,Points to notice: 1. 主动与被动的问题： I have a lot of books to read. This is a good book to read. (Cf. This is a good book to be read by very young children.) Tom is eager to please. Tom is easy to please. We have no time to lose (to be lost).,2. 转换为it结构，有的可以，有的不可以： One is too foolish to make the same mistakes again. It is foolish to make the same mistakes again. But: She is charming to look at. / It is charming to look at her. The river is too narrow to sail up. / It is too narrow to sail up the river. Key: “it” 是个傀儡主语，真正的主语是“to do”结构。比较： It is comfortable to sleep on Great Wall mattress. It is bitter to drink Brazilian coffee. (),3. 同词根的词结构一般相同： I am able to do it. I have the ability to do it. The victims family accused Simpson of first-degree murder. The accusation against Simpson of first-degree murder has been reported. Speaking differs from writing. Speaking is different from writing. Our happiness depends on the others smile. Our happiness has its dependence on the others smile.,Points to know about -ing participle: 1. 有的动词后面只能跟-ing，不能跟to do。p.356 e.g.: escape, avoid, insist on, admit, give up 特别是：VP + NP + into (from) + -ing 结构： My parents talked me into going to SCU. Lets hoax the kid into going to bed. Parents should keep their children from dangers. There is no way we can stop the accident from happening.,3) Participles of -ed and -ing 分词,2. 既能带to do，又能带-ing的动词分为两类：p.366 a) 意义差别不大者：attempt, begin, deserve, hate, Plan, intend, love, start, require,etc. I dont like to swim in such a bad weather. I dont like swimming in such a bad weather. The TV set needs repairing. The TV set needs to be repaired.,b) 意义不同者：P367 forget, remember, go on, leave off, stop, regret, mean I remember (forgot) telling him about it. Ill remember to tell him about it. We stopped having our coffee-break at 10 a.m. We stopped to have our coffee-break at 10 a.m. Dont you ever try using drugs! Not even once! He tried to move the stone, but it was too heavy.,Points to know about -ed participle: 1. different semantic meaning from -ing participle: p.374 an interesting show the interested audience a vanishing language a vanished language polishing oil polished shoes a developing country a developed country boiling water boiled water The time you enjoy wasting is not wasted time. I see the students lining up on the square. I see the students lined up on the square. I find her changing in many ways. I find her changed in many ways.,2. 少数几个过去分词作形容词和作补语时，所用的形态可能不同。 p.376-377 A drunken driver is one who drives when he is drunk. Blessed are those who live their lives in blessed calmness. When a candle is lit, it is a lighted candle. 3. 有些词（have）后的动词需要留意： I have my hair cut. / I have him cut my hair. make sth. understood / make sb. understand sth.,最后：Dangling participles (悬垂分词结构) 悬垂分词又叫无依着分词，只-ed或-ing分词结构找不到它的逻辑主语而处于“悬垂状态”。一般，分词从句的逻辑主语是主句的主语： Sleeping in the cradle, the infant is so peaceful. Defeated in the match, the athlete is in a bad mood. 但有时，这种关系不存在，语句可能导致误解： Rotten in the cellar, he threw the potatoes away. Opening the cupboard, the skeleton fell out. Walking in the park, the flowers are beautiful.,悬垂分词结构的可接受性：一般尽量避免，但如果不影响句意理解，在严谨性要求不高的文体中可以使用，如： Having failed, it seems to him that the world has come to its doomsday. 另有一些是约定俗成的表达结构，已被接受，如： Generally speaking, northerners are taller than southerners. Judging by the accent, the man is from Guangzhou.,（1）悬垂分词作状语表示说话人的看法。例如： Judging from（或 by）his accent, he must be from London. Strictly speaking, that school is not very old. He leads a very active life, considering his