情态动词用法归纳

1、情态动词用法归纳情态动词有 can （could）, may （might）, must, have to, shall （should, will （would）,dare （dared）, n eed （n eeded）, ought to等。 情态动词无人称和数的变化；不能单独使用，必须与其后的动词原形构成谓语一、can, could1）表示能力（体力、知识、技能）。Can you lift this heavy box?（体力）Mary can speak three Ian guages.（知识）Can you skate?（技能）此时可用be able to 代替。Can只有一般现

2、在时和一般过去式；而 be able to 则有更多的 时态。I ' ll not be able to come this after noon.当表示"经过努力才得以做成功某事”时应用 be able to ，不能用Can。如：He was able to go to the party yesterday evening in spite of the heavy rain.2）表示请求和允许。Can I go now? Yes, you can. / No, you can ' t.此时可与 may互换。在疑问句中还可用could,might代替，不是过去式，

3、只是语气更委婉，不能用于肯定句和答语中。Could I come to see you tomorrow? Yes, you can. （ No, I ' m afraid not.）3）表示客观可能性（客观原因形成的能力）。They' ve cha nged the timetable, so we can go by bus in stead.This hall can hold 500 people at least.4）表示推测（惊讶、怀疑、不相信的态度），用于疑问句、否定句和感叹句中。Can this be true?This can ' t be done

4、by him.How can this be true?二、may, might1）表示请求和允许。might比may语气更委婉，而不是过去式。否定回答时可用can't或mustn' t，表示"不可以，禁止”。-Might/ May I smoke in this room? No, you mustn ' t.- May/Might I take this book out of the room? Yes, you can. （No, you can ' t / mustn ' t.）用May I.?征徇对方许可时比较正式和客气，而用Can

5、 I.?在口语中更常见。2）用于祈使句，表示祝愿。May you succeed!3）表示推测、可能性（不用于疑问句）。might不是过去式，它所表示的可能性比may小。1. He may /might be very busy now.2. Your mother may /might not know the truth.三、must, have to1）表示必须、必要。You must come in time.在回答引出的问句时，如果是否定的，不能用must n't （禁止，不准），而用need n' t, do n' t have to （不必）.Must w

6、e hand in our exercise books today?Yes, you must. No, you don ' t have to / you needn' t.2）must是说话人的主观看法，而have to则强调客观需要。Must只有一般现在时，haveto有更多的时态形式。1. he play isn ' t interesting, I really must go now.2. I had to work whe n I was your age.3）表示推测、可能性（只用于肯定的陈述句）1. You' re Tom' s go

7、 od friend, so you must know what he likes best.2. Your mother must be wait ing for you now.四、dare, n eed1）dare作情态动词用时，常用于疑问句、否定句和条件从句中，过去式形式为dared。1. How dare you say I ' m unfair?2. He daren ' t speak English before such a crowd, dare he?3. If we dared not go there that day, we couldn '

8、; t get the beautiful flowers.2）need作情态动词用时，常用于疑问句、否定句。在肯定句中一般用must, have to, oughtto, should 代替。1. You needn' t come so early.2. - Need I fin ish the work today? Yes, you must. / No, you needn' t.3）dare和need作实义动词用时， 有人称、时态和数的变化。在肯定句中，dare后面常接带to的不定式。在疑问句和否定句中，dare后面可接带to或不带to的不定式。而need 后面只能

9、接带to的不定式。1. I dare to swim across this river.2. He doesn ' t dare （to） answer.3. He n eeds to finish his homework today.五、shall, should1）shall用于第一人称，征求对方的意见。What shall we do this evening?2）shall用于第二、三人称，表示说话人给对方的命令、警告、允诺或威胁。1. You shall fail if you don' t work hard.（ 警告 ）2. He shall have the

10、 book when I finish it.（允诺）3. He shall be pun ished.（ 威胁）六、will, would1）表示请求、建议等，would更委婉。Will / Would you pass me the ball, please?2）表示意志、愿望和决心。1. I will n ever do that aga in.2. They asked him if he would go abroad.3）would表示过去反复发生的动作或某种倾向。would表示过去习惯时比 used to正式，且没有“现已无此习惯”的含义。1. During the vacati

11、 on, he would visit me every other day.2. The wound would not heal.4）表示估计和猜想。It would be about ten o ' clock when she left home.七、should, ought to1）should, ought to 表示"应该”，ought to 表示义务或责任，比should语气重。1.1 should help her because she is in trouble.2. You ought to take care of the baby.2）表示劝告、

12、建议和命令。 should, ought to可通用，但在疑问句中常用should 。1. You should / ought to go to class right away.2. Should I open the win dow?3）表示推测should , ought to （客观推测），must（ 主观推测）。1. He must be home by now.（断定他已到家）2. He ought to/should be home by now.（不太肯定）3. This is where the oil must be.（直爽）4. This is where the oi

13、l ought to/should be.（含蓄）从高考题看情态动词的用法最近几年高考试题中常常借助语境来考查情态动词的基本用法及其区别，因此在平时学习 时准确理解和掌握情态动词的基本用法十分重要。情态动词的用法复杂多变，在高考试题中，命题者常常利用语境和句子之间意义上的细微差别来考查学生对情态动词的理解和掌握。对于情态动词，除了要求考生能够准确掌握它们的基本用法外，还要充分利用高考试题所设置的语境来分析句子之间所体现的特殊关系。下面就近几年来高考试题中出现的情态动词的考点进行归纳分析，以便同学们复习掌握。一、用“情态动词+have + done”结构表示对过去动作的推测，高考试题中常用过去时

14、态或过去的时间状语给以暗示。情态动词的这一用法可以用“对立统一”来概括。1 当试题的前句和后句在动作和意义上相互补充说明，且整个句意在动作和时间上是一个 整体时，我们可用“统一”关系来解决这样的试题。常见的结构有：must have done :表示对过去动作的肯定推测，常译作“一定做了”，只能用于肯定句中。其否定形式为 can' t/couldn ' t have done疑问式为 Can/Could.havedone?。could /might have done：表示对过去发生的动作的可能性推测，常译作“可能做了”。如：1） Sorry I ' m late .

15、I have turned off the alarm clock and gone backto sleep again .（北京 2000 春）A. might B . should C . can D . will该题前句说明了结果，后句接着说出了产生这种结果的可能性，对前句进行补充说明。分析选项可知本题应选 A2） My sister met him at the Grand Theater yesterday after noon, so heyour lecture .（上海 2000）A.could nt have atte ndedB. n eed n' t have

16、atte ndedC. mustn' t have attendedD. shouldn ' t have attended该题前句叙说一个客观事实，后句对前句进行补充说明，分析选项可知D两项不符合题意。故本题选A。又如：Jack yet, otherwise he would have telephoned me.(上海'97)A. mustn' t have arrivedB. shouldn ' t have arrivedC. can' t have arrivedD. n eed not have arrived(C)2.当试题的前后句

17、在动作和意义上构成转折关系时，常借助"but, however, instead ”等词来表示过去的动作与客观事实不符，这时我们就可以用“对立”关系来解决这样的试题。这种结构常见的有：should have do ne/ ought to have done :表示过去本应该做某事而实际上没有做。should not have done / ought not to have done:表示过去本不应该做某事但事实上却做了。need have done :表示过去本来有必要去做某事，但事实上没有做。need n ot have done:表示过去本来没有必要做某事，但事实上却做了。如

18、：3) I was really anxious about you. You home without a word. (NMET2001)A. mustn' t leave B .shouldn ' t have leftC.couldn ' t have left D .needn' t leave分析该题前后句之间的关系和语气可知，事实上是“本不应该离家出走却走了”，故本题选B。4) I told Sally how to get here, but perhaps I for her . ( NMET 94)A. had to write it out

19、B. must have writte n it outC. should have writte n it outD. ought to write it out由句中的连词but可知前后句之间是对立关系，分析题意可知本题应选Co二、考查情态动词基本用法之间的比较和辨析。最近几年高考试题中常借助具体的语境来考查考生对那些最常见的情态动词的基本用法的理解和掌握，因此在做这样的试题时应认真分析语境中所含的实际意义，并结合情态动词的基本含义和用法做出正确的选择。6) I hear you' ve got a set of valuable Australian coins . I have

20、 look?Yes, certainly.(北京 2002春)A. Do B . May C . Shall D . Should分析语境可知这是在征求对方的许可，may表示“允许、可以"，语气比较委婉shall常用于第一、三人称作主语的疑问句中，表示征求对方意见和指示，如果此空用shall，则意为“要(我)看一下吗？”，不符合上下文意思。故本题选Bo7) Mr Bush is on time for everything. How it be that he was late forthe opening ceremony?(上海 2001 春)A. can B . should

21、C . may D . mustmust be表示肯定的猜测，只能用于肯定句中，由题意可知本题应选A。8) Are you coming to Jeff ' s party?I ' m not sure . I go to the con cert in stead. (NMET2000)A. must B . would C . should D . might由题意和下句中的“I ' m not sure ”可知这段对话中存在一种可能性推测，might可以用来表示一种比较委婉的可能性判断，故本题选D。.下载可编辑9) Johnny, you A. won' t; can ' tC. shouldn ' t; must D mustn' t表示“不可以；禁止”10) Will you stay for lunchSorry, A.I mustn ' tBC.I needn ' tDplayhurt yourself . (NMET 96)with the knife, you B . must n' t; may can' t; should n 't，分析题意可知第二个空表示某种可能性