《英語 語法總結(jié)》word版.doc

《《英語 語法總結(jié)》word版.doc》由會員分享，可在線閱讀，更多相關(guān)《《英語 語法總結(jié)》word版.doc（80頁珍藏版）》請在裝配圖網(wǎng)上搜索。

英語語法總結(jié)全集 名詞和主謂一致 一、 名詞的分類 英語中名詞主要可以分為可數(shù)名詞和不可數(shù)名詞。 1．可數(shù)名詞 可數(shù)名詞一般都有單復(fù)數(shù)。單數(shù)時，名詞前可加不定冠詞a/an；復(fù)數(shù)時，前面可加數(shù)詞，名詞本身要改成復(fù)數(shù)形式。 可數(shù)名詞的復(fù)數(shù)有規(guī)則和不規(guī)則兩種變化。規(guī)則的名詞，只要在單數(shù)名詞之后加“s”，“es”或去“y”加“ies”就行，如：an umbrella, twelve umbrellas；a factory, three factories。不規(guī)則的名詞變化則要靠積累記憶，如：a mouse, ten mice；a policeman, six policemen。 有少數(shù)可數(shù)名詞，如sheep，works（工廠），Chinese等，它們的單復(fù)數(shù)同形：a sheep, four sheep；a chemical works, five chemical works。 此外，還有一些可數(shù)名詞只有復(fù)數(shù)形式，如clothes，trousers，cattle，police，people(人，人民)等。 英語名詞中還有一些合成詞，它們的復(fù)數(shù)形式有三種可能：1）后面的部分變成復(fù)數(shù)形式：grown-ups，boy students，grandchildren。2）前面的部分變成復(fù)數(shù)形式：passers-by，lookers-on，sons-in-law。3）前、后都變成復(fù)數(shù)形式：men doctors，women drivers。 2．不可數(shù)名詞 不可數(shù)名詞沒有單復(fù)數(shù)的變化，前面也不能加a/an，或數(shù)詞。但是我們可以用量詞來表示不可數(shù)名詞的數(shù)量，單復(fù)數(shù)表現(xiàn)在量詞上，如：a piece of paper；two pieces of paper。 在有些情況下，不可數(shù)名詞也可用a/an，表“一種”、“某種”的意思，如have a wonderful time，receive a good education，be made into a fine paper。 有時為了表示量大，不可數(shù)名詞的后面也可加“s”，如sands，ashes，waters等。 但是我們在學(xué)習(xí)不可數(shù)名詞的時候，特別要記住英語中有一些名詞，它們無論在什么情況下，前面都不能用a/an，后面也不可加“s”，如weather，information，等。 3．有的名詞既可是可數(shù)名詞，也可是不可數(shù)名詞 英語中有相當(dāng)一部分的名詞，既可以是可數(shù)，也可以是不可數(shù)，它們的意義有時略有不同，有時則完全不同。如：difficulty, success, time, work，paper，glass，等。 4．用于表示可數(shù)與不可數(shù)名詞的數(shù)量“多”“少”的常用詞和詞組 跟可數(shù)名詞連用的如：few, a few, many。 跟不可數(shù)名詞連用的如：little, a little, much。 可數(shù)與不可數(shù)都能用的是：a lot of , plenty of。 二、主謂一致 1．通常被看作單數(shù)的主語部分 1）不定式、動名詞和主語從句。 eg.. To see is to believe. Seeing is believing. What he said was different from what he did. 2）表示“時間”“距離”“金錢數(shù)量”的名詞。 eg. Twenty years is quite a long time. 10 kilometers doesn’t seem to be a long distance to Mira. 300 dollars is too much for this old coin. 3）數(shù)學(xué)式子。 eg. Two plus five is seven. 4）書報雜志、國家、單位的名字。 eg. The Times is published daily. The United States is a big country. 5）前面用a kind of, a sort of或this kind of, this sort of等詞組的名詞。 eg. This kind of tree(s) often grows well in warm weather. 6）代詞either, neither作主語。 eg. Either of the plans is good. Neither of them was carrying a weapon. 7）many a/ more than one 加單數(shù)名詞，或one out of加復(fù)數(shù)名詞作主語。 eg. Many a young man has tried and failed. More than one employee has been dismissed. One out of ten thousand computers was infected with the virus. 2．通常被看作復(fù)數(shù)的主語部分 1）一些只有復(fù)數(shù)的名詞如clothes, trousers, police等。 eg. These trousers are dirty. 但要注意比較：A new pair of trousers is what you need。 2）代詞both作主語。 eg. Both of them have received high education. 3．需要進(jìn)行分析才能確定的主語部分 1）代詞all, some,作主語。 所代的名詞是可數(shù)名詞，就看作復(fù)數(shù)；是不可數(shù)名詞，就看作單數(shù)。 eg. All is ready. (= Everything is ready.) All are present. (= All the people/students... are present.) 2）a lot of, lots of, plenty of, some, any, 20% of, half of...等詞組作主語。 所修飾的名詞是可數(shù)名詞，就看作復(fù)數(shù)；是不可數(shù)名詞，就看作單數(shù)。 eg. 70% of the surface of the earth is covered with water. 90% of the graduates from the high school go to university. 3）關(guān)系代詞who, which, that作主語。 由先行詞決定單、復(fù)數(shù)。 eg. The student who is talking with the principal is Tom. The students who have chosen physics will have a test tomorrow. 但要注意one of ...與only one of...所修飾的先行詞。 eg. He is one of the students in our class who have been to Beijing. He is the only one of the students who has been to London. 4）一些表示集體意義的名詞如family, team, class等。 當(dāng)這些名詞強(qiáng)調(diào)的是一個整體時，看作單數(shù)；當(dāng)它們強(qiáng)調(diào)的是這個集體中的成員時，看作復(fù)數(shù)。 eg. Happy families are all alike; every unhappy family is unhappy in its own way. My family are all early risers. 4．出現(xiàn)在句首，用連詞或介詞連接的兩個名詞或詞組 1）用both...and...連接的兩個名詞看作復(fù)數(shù)。 Both Kate and Jean are football players. 2）用or, either...or..., neither...nor..., not only...but also...連接的兩個名詞，由靠近動詞的名詞決定單復(fù)數(shù)。 Either you or I am to go. Not only the students but also the teacher has to observe the rules. 3）用as well as, (together) with, like, besides, but, except等連接的兩個名詞，由第一個名詞決定單復(fù)數(shù)。 eg. His eyebrows as well as his hair are now white. No one but these two peasants has been there. 實際上這些都是介詞短語提前，不是并列的主語。 4）用and連接的兩個名詞有幾種情況： a)看作復(fù)數(shù)。 eg. Tom and Mary are primary pupils. b) 在有every ... and every ..., each ... and each ... 的時候；或用and連接的兩個名詞表示的是一件東西或一個人時，看作單數(shù)。 eg. Every boy and every girl in our country has the right to go to school. Bread and butter is what he eats for breakfast every day. 高考真題試析： 01年23題 As a result of destroying the forests, a large ____ of desert ____ covered the land. A. number; has B. quantity; has C. number; have D. quantity; have 選B。因為第一格后的名詞desert是不可數(shù)名詞，所以A、C兩項排除；又desert做主語，謂語要用單數(shù)形式。 02年（春）26題 He is the only one of the students who ____ a winner of scholarship for three years. A. is B. are C. have been D. has been 選D。因為定語從句的先行詞是由only one of修飾，所以應(yīng)看成單數(shù)；另外后面有時間狀語for three years，所以用現(xiàn)在完成時態(tài)。 03年28題 The young dancers looked so charming in their beautiful clothes that we took ____ pictures of them. A. many of B. masses of C. the number of D. a large amount of 選B。 空格后面的名詞是復(fù)數(shù)，所以不可以選D，而many后不跟of用，所以A項排除；the number of的確是放在可數(shù)名詞復(fù)數(shù)的前面，但意思是“......的數(shù)量”，不符合題意。 03年（春）28題 Where and when to go for the on-salary holiday ____ yet. A. are not decided B. have not been decided C. is not being decided D. has not been decided 選D。此句是不定式做主語，看成單數(shù)。而C項的時態(tài)不對，所以只有D。 04年（春）30.題 No one in the department but Tom and I ____ that the director is going to resign. A. knows B. know C. have known D. am to know 選A。謂語動詞應(yīng)該跟no one一致，所以選A。 05年（春）28題 We have only a sofa, a table and a bed in our new apartment. We need to buy ____ more furniture. A. any B. many C. little D. some 選D。后面的名詞是furniture，不可數(shù)。而且整句的意思是“要買些家具”,是肯定意義，所以選D。 05年（春）42題 Telephone messages for the manager ____ on her desk but she didn’t notice them. A. were left B. was left C. was leaving D. were leaving 選A。句子的主語是messages，是復(fù)數(shù)，另外它與動詞“留（在桌上）”的關(guān)系是被動。 05年31題 Professor Smith, along with his assistants, ____ on the project day and night to meet the deadline. A. work B. working C. is working D. are working 選C。謂語的單復(fù)數(shù)跟Professor Smith一致，應(yīng)該是單數(shù)。 動詞的時態(tài)與語態(tài) 一、動詞的時態(tài) 英語的動詞可以有十六種變化，但現(xiàn)在常用的是十二種，其中有九種是高中學(xué)生必須掌握的，還有三種只要理解。現(xiàn)以動詞do為例，十二種時態(tài)的形式列表如下： 一般 進(jìn)行 完成 完成進(jìn)行 現(xiàn)在 do/does is/am/are doing have/has done have/has been doing 過去 did was/were doing had done *had been doing 將來 shall/will do *shall/will be doing *shall/will have done 過去將來 would do （打星號的為理解項目） 1．一般現(xiàn)在時態(tài) A)意義：現(xiàn)階段經(jīng)常反復(fù)發(fā)生的動作或現(xiàn)在的狀態(tài)。 eg. He gets up at six every morning. There is a big tree in the back yard. B)常用的時間狀語：always, often, usually, sometimes, seldom, never, every day, once a week,等。 C)表示一種真理、自然規(guī)律等，在間接引語中也仍然用一般現(xiàn)在時態(tài)。 eg. The scientist explained that the earth goes round the sun, but no one believed him then. D)在時間、條件等狀語從句中，代替將來時。 eg. If he is not busy, he will come to the party tomorrow. E)注意第三人稱單數(shù)時，動詞后面要加“s”。 2． 一般過去時態(tài) A)意義：過去的動作或狀態(tài)。注意，即使是剛剛發(fā)生的事情，時間非常短，也要用過去時態(tài)。如：Why! It’s you—Mary! I didn’t know you were here! B)常用的時間狀語：yesterday, last week, 3 years ago, just now, 等。 C)動詞過去式的規(guī)則變化（加ed）和不規(guī)則變化。 3．一般將來時態(tài) A)意義：將來要發(fā)生的動作或狀態(tài)。 B)常用的時間狀語：tomorrow, next moth, in two weeks, 等。 C)除了用shall/will之外的將來表達(dá)法： a) is/am/are going to do，意為“打算、準(zhǔn)備、馬上就要”。 eg. It’s going to rain. b) is/am/are to do，意為“（計劃好/安排好）要......” eg. The new underground railway is to be opened to traffic next year. c)is/am/are about to do，意為“馬上就要”。 eg. Hurry up! The plane is about to take off. d) 某些動詞（主要是一些表示位置移動的動詞）可用一般現(xiàn)在時態(tài)或現(xiàn)在進(jìn)行時態(tài)表示將來的動作。 eg. The train leaves for Beijing at 8:30 this evening. He is going to London next week. 4．現(xiàn)在進(jìn)行時態(tài) A)意義：表示在說話的同時或最近一個階段正在發(fā)生的動作。 B)常用的時間狀語：now, these days, at present, at the moment, 等。 C)有時可以和always, constantly, forever等時間狀語連用，表示說話人的某中特殊的感情。 eg. He is always thinking of others. Mrs Smith is constantly quarrelling with her neighbours. D)有些瞬間動詞可以用進(jìn)行時態(tài)表示“馬上就要......” eg. The old man is dying. E)英語中有些表示狀態(tài)、感覺、心理活動的動詞沒有進(jìn)行時態(tài)，如know, understand, believe, like, love, see, hear, seem, 等等。 5．過去進(jìn)行時態(tài) A)意義：表示過去某個時刻正在做的動作。 B)常用的時間狀語：this time yesterday, at 9:00 last night, 等。 C)有些動詞（主要是一些表示位置移動等的動詞和瞬間動詞）的過去進(jìn)行時態(tài)可以表示過去將來的意義。 eg. I was told that she was leaving for Australia the next morning. *6．將來進(jìn)行時態(tài) A)意義：表示將來某個時刻正在發(fā)生的動作。 B)常用的時間狀語：this time tomorrow, at 9:00 next Sunday morning, 等。 eg. What will you be doing at 9:00 on June 7next year? 7．現(xiàn)在完成時態(tài) A)意義：a. 表示過去某個時刻開始，一直持續(xù)到現(xiàn)在的動作或狀態(tài)。（只有部分延續(xù)性動詞，如live, work, study, 等可以表示這一意義） eg. I have lived in Shanghai since I was born. He has been married for half a year. b. 表示過去做過的某一個動作對現(xiàn)在的影響。 eg. I have seen this film. It’s fantastic! Jack is playing video games, because he has done his homework. B)常用的時間狀語：a. since 1990, for 9 years,等。 b. already, yet, just, now, this week, never, ever, so far, up till now, lately, in the past/last few years, 等。 C)b組所表示的現(xiàn)在完成時態(tài)與過去時態(tài)的區(qū)別：雖然現(xiàn)在完成時態(tài)b組表示的動作也是發(fā)生在過去，但它強(qiáng)調(diào)的是與現(xiàn)在的關(guān)系，而過去時態(tài)只表示過去發(fā)生的動作，敘述一個事實。試比較： eg. 1) He went to Beijing two days ago. He has gone to Beijing. 2) Henry lost his mobile phone yesterday, but found it later. Henry has lost his mobile phone again. D)瞬間動詞要表示“一直到現(xiàn)在”，不能直接用“完成時態(tài)加for”的方式，必須用其他句型。 eg. 他離開上海已經(jīng)三天了。 He has left Shanghai. He left three days ago. He has been away from Shanghai for three days. It is three days since he left Shanghai. 8．過去完成時態(tài) A)意義：表示過去某個時刻之前所做的動作，即“過去的過去”。所以一般要用過去完成時態(tài)的話，句子中或上下文一定有一個過去時態(tài)的動作或時間狀語做比較，才能用。 eg. He had learned English before he went to Canada. B)常用的時間狀語：by the end of last year 等。 C)在用間接引語時，主句的動詞是過去時態(tài)，用來替換直接引語中的過去時態(tài)或現(xiàn)在完成時態(tài)。 eg. He asked the girl, “Where have you been?” → He asked the girl where she had been. He said, “I cleaned the classroom yesterday.” → He said that he had cleaned the room the day before. D)有些動詞（如hope, wish, expect, think, intend, mean, suppose等）的過去完成時態(tài)可表示過去事實上沒有實現(xiàn)的希望、計劃等。 eg. I had hoped to attend the party, but I was too busy. *9．將來完成時態(tài) A)意義：表示在將來某個時刻之前將會完成的動作。 B)常用的時間狀語：by the end of next year等。 eg. You will have studied English for 10 years by the time you finish high school. 10．現(xiàn)在完成進(jìn)行時態(tài) A)意義：表示一個動作從過去開始，一直持續(xù)到現(xiàn)在。（同現(xiàn)在完成時態(tài)的第一種意義） B)常用時間狀語：since ..., for ..., so far, up till now 等。 C)現(xiàn)在完成進(jìn)行時態(tài)與現(xiàn)在完成時態(tài)的比較： 只有現(xiàn)在完成時態(tài)的第一種意義的那些動詞，它們的現(xiàn)在完成與現(xiàn)在完成進(jìn)行兩種時態(tài)表示的意義相同，可以互換使用。 eg. I have studied here for 3 years. = I have been studying here for 3 years. 而其他的一些動詞，使用兩種時態(tài)，意義就各不相同了。 試比較： The little boy has read the text.（小男孩已經(jīng)讀過課文了。） The little boy has been reading the text.（小男孩一直在讀課文。） 試翻譯：1）從上午九點開始我就一直在做功課。 I have been doing my homework since 9 in the morning. 2）今天的功課我已經(jīng)做好了。 I have done today’s homework. *11．過去完成進(jìn)行時態(tài) 意義：表示從過去某一時間開始的動作一直持續(xù)了一段時間再結(jié)束。（結(jié)束的時間點也在過去） eg. He had been searching for the watch for a half hour when we came back. 12．過去將來時態(tài) 意義：表示從過去某一時間看將要發(fā)生的動作或狀態(tài)，一般多用在間接引語中。 eg. He told me that he would read the book a second time. 二、動詞的語態(tài) 英語中的動詞可分為及物動詞和不及物動詞，以及系動詞。及物動詞有主動語態(tài)和被動語態(tài)；不及物動詞或動詞詞組（如happen, belong to, take place等）和系動詞（如become, seem, sound, look, taste,等）沒有被動語態(tài)。 1．以動詞do為例，被動語態(tài)的各種時態(tài)的表達(dá)方式如下表： 一般 進(jìn)行 完成 現(xiàn)在 is/am/are done is/am/are being done have/has been done 過去 was/were done was/were being done had been done 將來 shall/will be done shall/will be done 過去將來 would be done 各種時態(tài)在助動詞be上表示，動作由過去分詞體現(xiàn)。 2．注意在動詞詞組變被動的時候，原來詞組中的介詞或副詞不要漏掉。 eg. The villagers took good care of the wounded soldier. → The soldier was taken good care of by the villagers. 3．有些動詞既是及物動詞，又是不及物動詞，這些動詞比較少用被動語態(tài)。 eg. We begin our class at 8:00 every morning. → ? Our class is begun ... ? Our class begins at 8:00 every morning. 4．有少數(shù)動詞或動詞詞組可用主動形式，表示（從中文里我們所感覺的）被動意義。 eg. The book sells poorly. His translation reads better than yours. Who is to blame for the accident? 高考真題試析： 02年23題 He will have learned English for eight years by the time he ____ from the university next year. A. will graduate B. will have graduated C. graduates B. is to graduate 選C。雖然句子的時間狀語是next year，但是“他從大學(xué)畢業(yè)”是以by the time引出的狀語從句，在狀語從句中，用現(xiàn)在時態(tài)代替將來時態(tài)。 02年24題 I feel it is your husband who ____ for the spoiled child. A. is to blame B. is going to blame C. is to be blamed D. should blame 選A。因為詞組be to blame for這一詞組用主動形式來表示中文中“該為某事受到責(zé)備”的被動意義。 02年29題 “Will you go skiing with me this winter vacation?” “It ____.” A. all depend B. all depends C. is all depended D. is all depending 選B。It all depends.是習(xí)慣說法，意思為“要看情況而定了”，不用將來時態(tài)，也不用被動語態(tài)。 03年32.題 I thought Jim would say something about his school report, but he ____ it. A. doesn’t mention B. hadn’t mentioned C. didn’t mention D. hasn’t mentioned 選C。從前面一句I though可以看出是過去時態(tài)，用but連接的兩個并列句中的動作是發(fā)生在同一時間，所以后面的動詞也應(yīng)該是過去時態(tài)。 04年29題 The first use of atomic weapons was in 1945, and their power ____ increased enormously ever since. A. is B. was C. has been D. had been 選C。因為句子的時間狀語是ever since，意即“自從那時起”（“那時”指前面講到的1945年），所以是現(xiàn)在完成時態(tài)。 04年30題 The number of deaths from heart disease will be reduced greatly if people ____ to eat more fruit and vegetables. A. persuade B. will persuade C. be persuaded D. are persuaded 選D。因為“人們”和“說服”是動賓關(guān)系，所以用被動語態(tài)。 05年30題 More than a dozen students in that school ____ abroad to study medicine last year. A. sent B. were sent C had sent D. had been sent 選B。因為學(xué)生是被送到國外學(xué)醫(yī)的，所以要用被動語態(tài)，而句末 時間狀語表明要用過去時態(tài)。 06年27題 Send my regards to your lovely wife when you ____ home. A. wrote B. will write C. have written D. write 選D。這是祈使句中的狀語從句的動詞，所以用一般現(xiàn)在時態(tài)代替將來時態(tài)。 06年32題 When he turned professional at the age of 11, Mike ____ to become a world champion by his coach and parents. A. expected B. was expecting C. was expected D. would be expected 選C。根據(jù)整個句子的意思，可以判斷，是他的教練和父母期盼馬克成為世界冠軍，所以用被動語態(tài)，時間在他7歲的時候，顯然是過去時態(tài)。 07年28.題 “Did you tidy your room?” “No, I was going to tidy my room but I ____ visitors.” A. had B. have C. have had D. will have 選A。根據(jù)前面的疑問句，可判斷談?wù)摰氖沁^去的事情，而且回答的前半句也說明了時態(tài)：“我正要打掃屋子，但我有客人來訪了”是過去時態(tài)。 07年30題 With the help of high technology, more and more new substances ____ in the past years. A. discovered B. have discovered C. had been discovered D. have been discovered 選D。全句的時間狀語是in the past years，是典型的現(xiàn)在完成時態(tài)的時間狀語，而且“發(fā)現(xiàn)”與“新的物質(zhì)材料”是動賓關(guān)系。 情態(tài)動詞 一、can, may, must 根據(jù)意思與習(xí)慣用法，我們可以把can, may, must分成以下兩組用法，方便學(xué)習(xí)與掌握。 1．第一組用法見下表（主要在初中的時候我們所掌握的）： 詞義 肯定 否定 疑問 過去式 can 能、會 can can’t Can...? could may 可以 may mustn’t/may not May...? might must 必須 must needn’t Must...? must/had to A) can a) can的肯定、否定、疑問及過去式的例句： eg. Computers can do a lot of things for us. Money cannot buy everything. Can you speak French? I could run very fast when I was young. b) can與be able to can與be able to的意思相近，經(jīng)?？梢曰Q使用，但是be able to除了有一般現(xiàn)在與過去時態(tài)之外，還有將來、完成等時態(tài)，所以要表示將來能夠或已經(jīng)能夠做什么事，就要用be able to。 eg. You will be able to communicate with foreigners fluently if you finish the course. The baby has been able to one or two simple sentences. 在用過去式的時候，could與was able to的意思不同，could表示的是“當(dāng)時能夠做某事”的意思，而was/were able to表示的是“當(dāng)時能夠，并且成功地做到了”的意思。 試比較： Einstein was able to flee Germany when Hitler came into power. I could pass the examination, but I was too careless. c) could在疑問句時用意表示請求，意義同can，是一種比較客氣的表達(dá)方式。 eg. Could you give me a hand? B) may a) may的肯定、否定、疑問及過去式的例句： eg. You may choose anyone here you like. —May I leave now? —Yes, of course/Sure. Go ahead. —No, you mustn’t. （注：口語中也能用cannot。） I was told that the boss might come to the office before 9 b)mustn’t與may not. mustn’t一般是說話人表示“不可以”或“禁止”，而may not一般是指按規(guī)定“不允許”的意思。試比較： You mustn’t leave the bike here. The sign on the wall reads, “Visitors may not feed the animals in the zoo.” c) may可放在句首，表示“祝愿”。 eg. May our friendship last forever. d) might有時用在疑問句中，只是一種比may更客氣一點，而非過去式。 eg. Might I have a few words with you, sir? C) must a) must的肯定、否定、疑問及過去式的例句： eg. Everyone must obey the rules. —Must I finish the work today? —Yes, you must. —No, you needn’t/don’t have to. He told me he must/had to see a doctor tomorrow morning. b) must與have to 用must更強(qiáng)調(diào)主觀上“必須”，而have to 更強(qiáng)調(diào)客觀上的“不得不”。 在間接引語中，主句動詞是過去式時，用had to多，但must也可以用。 have to有現(xiàn)在、過去和將來三種時態(tài)。 c) must有時可以表示“偏偏”“非...不可”的意思。 eg. Why must you make such a mess when the visitors are coming? 2．第二組用法見下表： 詞義 肯定 否定 疑問 過去式 進(jìn)行式 can 可能/一定 / cannot Can...? can’t have done can’t be doing may 可能 may may not / may have dong may be doing must 一定 must / / must have done must be doing a) can, may, must的第二種用法，是用來表示說話人的一種推測。其中may與must的區(qū)別其實是說話人對可能性大小所做判斷的區(qū)別，覺得可能性大，就用must，可能性小，就用may。而can與may, must是肯定、否定、疑問分工的不同。 現(xiàn)在時舉例： —Can Tom be in the classroom? —Yes, he must be there. 或—Yes, he may be there, but I’m not quite sure. 或—No, he can’t be there, because he hasn’t come to school today. 過去時舉例： I must have been asleep. I didn’t hear your footsteps. David became angry at the meeting. He may have misunderstood what I meant. James can’t have forgotten the examination yesterday. There must have been something wrong with him, I believe. b)表示可能性的否定句中有時也可用may，但意思與cannot有所不同。may not一般解釋為“可能不”，而cannot解釋為“不可能” c)表示可能性，也可以用might和could，但并非may和can的過去式，而是表示說話人覺得可能性實在是比較小了，有虛擬的意味。跟may與can一樣，might用在肯定句，could用在否定句和疑問句。might do的過去式是might have done，could的過去式是could have done。 eg. —Could it be Susan at the door? —Yes, it might be her.（現(xiàn)在口語中也可用could be回答） *d) could have done也可以用在肯定句里，表示過去有這種可能，但事實上沒有發(fā)生（虛擬語氣的用法）。 eg. It was dangerous to do so. You could have killed yourself! 二、shall, will, would 1．用在一般疑問句中，表示征求對方的意見。第一、第三人稱用shall，第二人稱用will或would。 eg. Shall turn on the TV? Shall my brother go with us? Will/Would you do me a favour? 2．shall與第二、第三人稱連用，用在肯定、否定句中，表示“命令、允諾、警告、威脅，及說話人的意愿和決心”。 eg. You shall do it at once! He shall have the money when he finish his work on time. You shall fail if you don’t work hard. If Shylock breaks the law, everything he has shall be taken away from him. 3．will在陳述句中可用于任何人稱，表示“意愿、意志、決心”等。有時也可用在條件句中。 eg. I will help you at any time if necessary. The captain will land you safe in Liverpool, if you will be man. 4．will和would可以表示習(xí)慣性反復(fù)發(fā)生的動作，或在某一條件下，一定回發(fā)生的動作。這時，will一般指“現(xiàn)在”，would一般指“過去”。 eg. Oil will float on water, because it is lighter. He would take a walk after supper when he lived here. 上面例句中的would可以用used to來替換。used to也表示“過去常?！保玼sed to還隱含了“現(xiàn)在不再這樣了”的意思。而would則沒有這種意思。 eg. He used to smoke, but he has given it up now. 三、should/ought to 1．可以表示一種必要性、義務(wù)，解為“應(yīng)當(dāng)、應(yīng)該”?？梢耘c任何人稱連用，并用在肯定、否定、疑問句中。但疑問句時用should更多一些。 eg. You should/ought to pay more attention to your spelling. 2．可以表示一種推測，解為“應(yīng)該是”。用于任何人稱的肯定、否定、疑問句。它還有進(jìn)行和完成兩種形式：should/ought to be doing（對現(xiàn)在正在進(jìn)行的動作的推測）和should/ought to have done（表示與過去的事實相反，“本來應(yīng)該”的意思）。 eg. They should be here by now. The students should be doing the experiment in the lab. You should have come here ten minutes earlier. 3．should有時可以表示說話人驚訝的感覺，解為“竟然”。 eg. I have never imagined that he should say so at the meeting. 四、need和dare need和dare兩詞，都既可作為情態(tài)動詞，又可作為實意動詞，所以復(fù)習(xí)的重點是分清在句子中它們分別是哪種動詞。 1．need解為“需要、必須”。 A) 作為情態(tài)動詞時，多用于疑問句和否定句。 eg. —Need I do it again? —No, you needn’t. 注意：與Must I do it again?的意思相近，但用need問，問的人一般希望得到的是否定的回答；而用must問，問話的人一般希望得到的是肯定回答。 B) 作為實意動詞，可用于各種句型，是及物動詞，可以跟名詞做賓語。 eg. We need another five workers to do the work. C) needn’t have done與didn’t need to do的區(qū)別 needn’t have done和didn’t need to do分別是情態(tài)動詞用法與實意動詞用法的過去形式，但是所表示的意義不同。needn’t have done意思是“本來不必”，言下之意是“做了不必要做的事了”；而didn’t need to do意思是“當(dāng)時不必要”，言下之意是“當(dāng)時不必要，因此可能就沒有做”。 試比較：She was too nervous to reply, but fortunately she didn’t need to say anything. 她緊張得無法答復(fù)，但幸運的是，她那時什么也不必說。 You needn’t have mentioned it to him, because he had been told everything before. 你本來不必跟他提這件事的，之前已經(jīng)有人把一切都講給他聽了。 2．dare解為“敢”。 A) 作為情態(tài)動詞時，多用于疑問句和否定句。 eg. Dare you say that to your boss? The little boy dare not face his teacher. 但是dare的固定詞組“I dare say...”，用在肯定句中。 eg. He’ll come again, I dare say. 注意：dare作為情態(tài)動詞時，它的過去式是dared。 eg. The