1、英語(yǔ)語(yǔ)法知識(shí)難點(diǎn)(三)編 稿：李俊和審 稿：畢 勤 責(zé)編: 隋 瑜(十)情態(tài)動(dòng)詞與助動(dòng)詞I 要點(diǎn)助動(dòng)詞本身無意義，在句中幫助主要?jiǎng)釉~構(gòu)成一定的時(shí)態(tài)，語(yǔ)態(tài)、語(yǔ)氣，或是幫助構(gòu)成否定句和疑問句，常用的助動(dòng)詞有be, do, have, shall(should), will(would).情態(tài)動(dòng)詞表一定的詞義，本身并不表示動(dòng)作或狀態(tài)，而僅僅表達(dá)說話人的態(tài)度，它在句中須和主要?jiǎng)釉~一起構(gòu)成謂語(yǔ)，主要的情態(tài)動(dòng)詞有 can(could), may(might), must, have to, ought to, need, dare, shall, should, will, would.1、 can 能，

2、可以，表說話人同意，許可還可表客觀條件許可，如 :You can go now.提建議或請(qǐng)求時(shí)可用 can I, can you 表客氣，如 Can I buy you a drink?can 和 be able to 表能力時(shí)的區(qū)別。can 表一般具有的能力， be able to 表在特定條件下的能力， 如 :Although the driver was badly hurt, he was able to explain what had happened.2、 may( 1)、可以，表說話人同意，許可或請(qǐng)求對(duì)方許可。 You may go.(2)、(現(xiàn)在和將來)可能，也許，只用于肯定

3、句和否定句中，如 He may not be right.3、 must, have tomust 表主觀上的必須， have to 表客觀上的必須，如 :It's getting late. I have to go. -Must I go now. -Yes, you must.(No, you needn't./ No, you don't have to.)4、 need, dare 這二詞有實(shí)意動(dòng)詞和情態(tài)動(dòng)詞兩種詞性， 如用作實(shí)意動(dòng)詞后接動(dòng)詞不定式to do，如用作情態(tài)動(dòng)詞后接動(dòng)詞原形。 Need I go now? -Yes, you must./No, y

4、ou needn't.)5、 shall 用于第一人稱疑問句中表說話人征求對(duì)方的意見或向?qū)Ψ秸?qǐng)求，如， Shall we begin our lesson?用于二、三人稱陳述句，表說話人命令、警告、允諾、威脅等口吻，如 : You shall fail if you don't work harder.6、 should 表應(yīng)該，意為有責(zé)任，有義務(wù)。如 :We should try our best to make our country more beautiful.7、 will 表有做某事的意志、意愿、安心、打算，如 "Will you lend me your

5、 book?" "Yes, I will." ，8、 should have done 表應(yīng)該做而未做must have done 表對(duì)過去事實(shí)的肯定推測(cè)could have done 表本可以做某事9、判斷句：肯定句用must, 否定句用 can't, 不太肯定用 may, mightHe must be in the office now.He must have gone to bed, for the light is out.He can't be in the office. He is at home.He couldn't

6、have cleaned the classroom, because he didn't come here today.He might be in the office, I am not sure.He might have cleaned the room, I suppose.II 例題例 1， They to walk in the street at night.A. didn't dare B. not dared C. not dare D. dared not解析，該題答案為 A， 此空需選一動(dòng)詞作謂語(yǔ)，因?yàn)楹竺媸?to walk, didn't

7、dare 是行為動(dòng) 詞 dare 過去時(shí)態(tài)的否定形式。例 2， When he was very old, Mr. Smith sit for hours without saying a word.A. would B. should C. must D. used解析，該題答案為 A, would 此處表過去的傾向性，習(xí)慣性動(dòng)作，意為 "總是 "如: Whenwe were children, we would go swimming every summer.（十一）句子種類I 要點(diǎn)句子按使用目的可分為陳述句、疑問句、祈使句和感嘆句；按結(jié)構(gòu)又分為簡(jiǎn)單句、并列句和復(fù)合句

8、。1、陳述句的否定（ 1） 在含有賓語(yǔ)從句的主從復(fù)合句中， 當(dāng)主句的謂語(yǔ)動(dòng)詞是think, expect, believe, suppose,guess, fancy, imagine 等，且主句主語(yǔ)是第一人稱時(shí)，賓語(yǔ)從句謂語(yǔ)的否定習(xí)慣上要移到主句 謂語(yǔ)上，如 : I don't think he is right.（ 2） 含有否定意義的副詞 never, seldom, hardly, scarcely, rarely, barely 的句子應(yīng)視 為否定句，如 : I have never been there before.2、反意疑問句（ 3） ） need 和 dare 既可

9、作情態(tài)動(dòng)詞， 又可作實(shí)意動(dòng)詞， 在反問部分須加以區(qū)別， 如 Weneedn't leave, need we? We don't need to leave, do we?（ 2） 陳述部分出現(xiàn)否定意義的副詞或代詞如 never, seldom, few, hardly, little等時(shí)，反問部分須用肯定形式如： He seldom comes, does he?（ 3） 陳述部分用不定代詞作主語(yǔ)時(shí)，反問部分的主語(yǔ)用 it ，如： Nothing can stop me, canit?陳述部分用 everybody, everyone, somebody, someone ，

10、等作主語(yǔ)時(shí)，反問部分常用 it ，有 時(shí)也用 they ，如 :Everybody knows that, don't they?（ 4） 陳述部分包括used to 時(shí)， 反問部分可有兩種形式， 如 : You used to get up early, usedn't（didn't） you?（5）陳述部分是"there + be"結(jié)構(gòu)時(shí)，反問部分用 there ,如:There's something wrong with you, isn't there?（ 6） 陳述部分是含有賓語(yǔ)從句的主從復(fù)合句時(shí)，反問部分的主語(yǔ)和謂語(yǔ)應(yīng)和

11、主句保持一致，如 : He never told others what he thought, did he?但，如果是I think , I believe 等 + 賓語(yǔ)從句時(shí)，反問部分須和從句的動(dòng)詞保持一致，如，I don't think he is right, is he? I don't believe he does that, does he?3、感嘆句用 what 或 how,What a beautiful park it is.How beautiful a park it is. How beautiful the park is.How we work

12、ed!4、祈使句Take care!Don't stand there.Please open the door for the old lady.II 例題例 1， Don't forget to post the letter, ?A. will you B. do you C. won't you D. shall you解析：該題答案為 A， 在否定句、 祈使句后只用 "will you"? ，但肯定的祈使句后可用如， Wait for me, will (won't, can, can't, could) you?例 2，

13、Let's go out for a walk, ?A. will you B. won't you C. shall we D. do we解析：該題答案為 C, let's后加上shall we來表語(yǔ)氣婉轉(zhuǎn)、客氣，而在let us后加上will you。例 3， He hardly writes to you, ?A. doesn't he B. does he C. do they D. has he解析：該題答案為 B， hardly 否定副詞，反問部分要用肯定形式。（十二）各種從句I 要點(diǎn)根據(jù)從句在句中的句法功能，從句可分為名詞性從句、定語(yǔ)從句和狀語(yǔ)從

14、句。1、 名詞性從句（ 1） 主語(yǔ)從句What he wants is a piece of paper.It is believed that he can solve the problem.注：主語(yǔ)從句的謂語(yǔ)動(dòng)詞用單數(shù)。（ 2）賓語(yǔ)從句I don't know how to solve the problem.Do you know where he lives?（ 3）表語(yǔ)從句The problem is who can help me.This is why I came here.（ 4）同位語(yǔ)從句I have no idea where he went.I heard t

15、he news that he would come.同位語(yǔ)從句用 that 引導(dǎo)， 常跟在 fact, idea, news, promise, thought, message, hope, belief, doubt 等詞后， that 在從句中不作任何成分。2、定語(yǔ)從句在復(fù)合句中，修飾某一名詞或代詞，或修飾整個(gè)主句的從句叫做定語(yǔ)從句，引導(dǎo)定語(yǔ)從句的關(guān)系代詞有 who, whom, whose, which, that, as, 和關(guān)系副詞when, where, why 。（ 1） that 指物時(shí)一般可與which 互換，但在下列情況下，要用 that 而不用 which 。a. 先

16、行詞有 all, everything 等不定代詞時(shí)，如，Everything （that） he did is wrong.b. 先行詞被 all, every, no, some, any, little, much等修飾時(shí)，如，I'll read all the books （that） you lend me.c. 先行詞被序數(shù)詞或形容詞最高級(jí)修飾時(shí)，This is the first letter (that) the boy has written.d. 先行詞被 the only, the very, the same, the last修飾時(shí)，如He is the ve

17、ry man (that) I'm looking for.e. 只用 which 的情況在介詞后或在非限定性定語(yǔ)從句中This is the book about which we have talked a lot.The book, which he gave me yesterday, is very interesting.f. where 和when作關(guān)系副詞This is the room where I worked.This is the room which I stayed in.I remembered the day when we lived there.I

18、 remembered the day that I spent there.g. as 和 whichas 可以放于句首，而 which 不可以As you know, he is good at English.three of them 和 three of whichI have a lot of books, three of which are in Russian.I have a lot of books and three of them are in Russian.3、狀語(yǔ)從句在復(fù)合句中起狀語(yǔ)作用的從句叫做狀語(yǔ)從句。 狀語(yǔ)從句可分為時(shí)間狀語(yǔ)、 地點(diǎn)狀語(yǔ)、 原因狀語(yǔ)、目的狀

19、語(yǔ)、結(jié)果狀語(yǔ)、條件狀語(yǔ)、行為方式狀語(yǔ)、比較狀語(yǔ)、讓步狀語(yǔ)等多種。II 例題例 1、 I accept the gift or refuse it is none of your business.A. If B. Whether C. Even if D. No matter when解析：該題答案為B。 whether 可以和 or 連用， if 不可以，此外if 一般僅用于賓語(yǔ)從句。例 2、 The way these comrades look at problems is wrong.A. where B. in that C.X D. with which解析：該題答案為 C,先行詞

20、是way,定語(yǔ)從句中用that或in which來引導(dǎo)或不填。例 3， a long time since I saw you last time.A It was B. It is C. It had been D. It can be解析：該題答案為 B, It is + 時(shí)間數(shù)+ since引導(dǎo)的從句是一個(gè)句型，意為"從時(shí)候以來過了多久了。 "（十三）主謂一致I 要點(diǎn)謂語(yǔ)受主語(yǔ)支配， 須和主語(yǔ)在人稱和數(shù)上保持一致， 這叫做主謂一致， 主謂一致包括語(yǔ)法一致、意義上一致和就近一致。1、語(yǔ)法上一致（ 1）、以單數(shù)名詞或代詞，動(dòng)詞不定式短語(yǔ)、動(dòng)名詞短語(yǔ)或從句作主語(yǔ)時(shí)，謂語(yǔ)動(dòng)詞

21、要用單數(shù)，主語(yǔ)為復(fù)數(shù)時(shí)，謂語(yǔ)用復(fù)數(shù)，如，To work hard is necessary for a student.（2）、用and或bothand連接的并列主語(yǔ)，謂語(yǔ)動(dòng)詞用復(fù)數(shù)，如，Both he and I are right.但并列主語(yǔ)如果指的是同一人，同一事物或同一概念，謂語(yǔ)動(dòng)詞用單數(shù)，如 , His teacher and friend is a beautiful girl.（ 3）、主語(yǔ)是單數(shù)時(shí)，盡管后面跟有as well as, but ,except, besides, with ,along with,together with, like 等，謂語(yǔ)動(dòng)詞仍用單數(shù)，如，T

22、he teacher as well as his students is excited.（4）、某些不定代詞，如做主語(yǔ)，謂語(yǔ)動(dòng)詞要用單數(shù)，如:Everyone has a book.（ 5）、一些只有復(fù)數(shù)形式的名詞，如people, cattle, clothes 等作主語(yǔ)時(shí)，謂語(yǔ)動(dòng)詞要用復(fù)數(shù)，如， A lot of people are dancing outside.2、意義上一致（ 1）、表時(shí)間、距離、價(jià)格、度量衡等的名詞作主語(yǔ)時(shí)，謂語(yǔ)動(dòng)詞通常用單數(shù)，如，Twenty years is not a long time.（ 2）、表示總稱意義的名詞public, police, cattle,