need-must用法及練習(xí).doc

need用法一用作實(shí)義動(dòng)詞1need sth.這是need最常見(jiàn)的用法之一，其后的賓語(yǔ)可以是名詞，也可以是代詞。如：1). The soup needs salt.2). They dont need afraid any more. 3). Does he need any help? 2need doing 與 need to be done通常物做主語(yǔ)，need后面可跟動(dòng)名詞作賓語(yǔ)，這種情況下應(yīng)注意兩點(diǎn)：.主動(dòng)形式的動(dòng)名詞doing具有被動(dòng)的含義；.該動(dòng)名詞可以改為其動(dòng)詞不定式的被動(dòng)形式而句子的意義不變。例如：4). The door needs painting. = The door needs to be painted. 5). Your car needs repairing. = Your car needs to be repaired. 3need to do sth.作為實(shí)義動(dòng)詞，need后面需要接帶to的動(dòng)詞不定式,表示有義務(wù)或責(zé)任去做某事。如：6). What do we need to take for the party? 7). Will we need to show our ID card? 8). I need to take good care of my sister. 二用作情態(tài)動(dòng)詞沒(méi)有人稱(chēng)和數(shù)的變化。不論主語(yǔ)是第幾人稱(chēng)，不論主語(yǔ)是單數(shù)還是復(fù)數(shù)，情態(tài)都詞都無(wú)形式變化；不能單獨(dú)充當(dāng)謂語(yǔ)。情態(tài)動(dòng)詞必須與一個(gè)實(shí)義動(dòng)詞一起構(gòu)成復(fù)合謂語(yǔ)，并且這個(gè)實(shí)意動(dòng)詞要始終是動(dòng)詞原形。變?yōu)榉穸ň鋾r(shí)只需在情態(tài)動(dòng)詞之后加not。9)You neednt do it again10)He neednt worry about it變?yōu)橐蓡?wèn)句時(shí)只需將情態(tài)動(dòng)詞提到主語(yǔ)的前面。例如：11). Need I type this letter again? 12）Need I stay here any longer?No, you neednt. Yes, you must. 三用作名詞need作為名詞，含義為“缺乏，需要”；其復(fù)數(shù)表示“基本需要”。要掌握兩個(gè)詞組：in (great) need of（急需） 與meet the needs of(滿足的需要)。例如：13). Theres no need for you to try again. 14). The factory is in great need of funds.“need+have+done”表示本來(lái)需要做某事而沒(méi)有做。“neednt+have+done”則表示“本來(lái)不需要做某事而做了”。I neednt have bought so much wineonly five people came. He need have hurried to the station. In that case, be wouldnt have missed the train. you need not have said that“should+have+done”意思是“本來(lái)應(yīng)該做某事，而實(shí)際沒(méi)做。” “shouldnt+have+done”表示本來(lái)不應(yīng)該做某事，而實(shí)際做了。含有指責(zé)對(duì)方或自責(zé)的含意。1. Tom, you are too lazy. The work should have been finished yesterday. 2. Look, Tom is crying. I shouldnt have been so harsh on him. 3 you should have told me “must+have+done”表示對(duì)過(guò)去事情的肯定推測(cè)，譯成“一定做過(guò)某事”，該結(jié)構(gòu)只用于肯定句。1. It must have rained last night, for the ground is wet. 2. You must have been mad to speak to the servant. must的用法1.must 表示“必須”、“應(yīng)該”。例如：We must protect our environment. Everyone must obey the rule.2. must的否定形式must not表示“不應(yīng)該”、“禁止”、“不準(zhǔn)”。語(yǔ)氣比較強(qiáng)烈。例如：You mustnt speak like that. You mustnt be late for school.3.在回答must的問(wèn)句時(shí)，肯定形式用must來(lái)回答，但否定形式用neednt 或dont have to來(lái)回答。而不用mustnt來(lái)回答。例如：Must I be home before 8 oclock?(8點(diǎn)之前我必須回家嗎？) Yes, you must. No, you neednt./No, you dont have to. （是，你必須。） （不，你不必。）4.must還可表示推測(cè)，意思是“一定”、“必定”，一般只用于肯定句中。分三種情況：1.）對(duì)于現(xiàn)在狀態(tài)的推測(cè)，我們用：must +v.（狀態(tài)動(dòng)詞或系動(dòng)詞），例如：He must be at home.(他準(zhǔn)在家里。）There must be some children in the room.（房間里準(zhǔn)有些孩子。）2.）對(duì)于現(xiàn)在動(dòng)作的推測(cè)，我們用：must +be + doing（行為動(dòng)詞），例如：They must be cleaning their room.(他們準(zhǔn)是在打掃房間。）He must be watching TV.（他準(zhǔn)是在看電視。）3.）對(duì)于過(guò)去事實(shí)的推測(cè)，我們用：must +have +過(guò)去分詞，例如:It must have rained last night.(昨晚準(zhǔn)是下雨了。）I didnt hear the phone. I must have been asleep.（我沒(méi)有聽(tīng)到電話，我準(zhǔn)是睡著了。）練習(xí)一Choose the right answer.( ) 1. You_any help, do you? A. dont need B. neednt C. need D. doesnt need( ) 2. -Must I stay at the office this afternoon? -No, you . A. dont B. neednt C. dont need D. cant( ) 3. Tom get up a little earlier tomorrow. A. needs B. need C. need to D. needs to( ) 4. Need the doctor _ with you tonight? A. staying B. stay C. stays D. to stay ( ) 5. Look! Your shirt is so dirty. It . A. need washing B. need to wash C. needs washing D. need wash( ) 6. The supply cant the demand. A. meet need of B. meet the need of C. meet the needs of D. meet needs of( ).7. The hospital is blood. A. in great need of B. on great need of C. in great need with D. on great need with( ) 8. Your room is full of dust. It . A. need clean B. need cleaning C. need to be cleaned D. needs to be cleaned( ) 9. David anything to drink? A. Need, B. Needs, C. Doesneed D. Doneed( ) 10. You to the meeting tomorrow if you have something important to do. A. neednt to come B. dont need come C. dont need coming D. neednt come二.Fill in the blanks using have to, have got to, must, should, ought to, had better.1.You _ not get down until the bus has stopped.2.They _ be encouraged to speak English after class.3.You often _ wait a long time for a bus.4.We _ go and see Mary tomorrow, but I dont think we will.5.I _ not miss my train.6.When traveling, you _ take care of your health.7.In some parts of the world, you _ boil the water before drinking it.8.If you have a stomach pain, you _ drink hot weak tea.9.You _ not swim immediately after a heave meal.10.You _ not wake me up when you come in.三 Trans