高中英语语法总结大全之情态动词
情态动词主要用法总结
情态动词主要用法总结情态动词是用来表示说话人的态度、情感或意愿的动词。
情态动词有can、could、may、might、shall、should、will、would、must、need 等。
以下是情态动词的主要用法总结：1.表示能力：- Can：表示一般的能力或技能，意为“能够”。
- Could：表示过去的能力或技能，意为“能够”。
2.表示许可或允许：- Can：表示一般的许可或允许，意为“可以”。
- May：表示正式的或礼貌的许可，意为“可以”。
3.表示可能性：- May：表示可能性较大，意为“可能”。
- Might：表示可能性较小，意为“可能”。
4.表示意愿或请求：- Shall：用于第一人称中，表示提议、请求或建议，意为“将”。
- Should：用于第一人称或第三人称中，表示忠告、建议或期望，意为“应该”。
- Will：用于第一人称和第三人称中，表示意愿、决心或承诺，意为“将”。
- Would：用于第一人称和第三人称中，表示客气的请求、建议或愿望，意为“将”。
5.表示必要性或推测：- Must：表示必须性或应该性，意为“必须”。
- Should：表示推测、猜测或可能性较大的必要性，意为“应该”。
6.表示时间或条件：- Will/Would：表示未来时间或条件，意为“将/将会”。
7.表示推测或假设：- Must：表示肯定的推测，意为“一定”。
- May/Might：表示可能的推测，意为“可能”。
需要注意的是，情态动词本身没有人称和数的变化，后面的动词应为原形。
另外，他们常常与动词的原形连用构成谓语，可以用于各种句型，例如肯定句、否定句、疑问句等。
高中英语知识点归纳情态动词和一般现在时的否定和疑问句总结
高中英语知识点归纳情态动词和一般现在时的否定和疑问句总结情态动词 (Modal Verbs) 是英语中一类特殊的动词形式，用来表示说话人对某种行为或状态的态度、推测、可能性、必要性、能力等。
一般现在时的否定句 (Negative Sentences in Simple Present Tense) 是用来陈述某种情况或事件常态发生的句子形式，表达否定的意思。
一般现在时的疑问句 (Interrogative Sentences in Simple Present Tense) 是用来询问某件事情是否发生或存在的句子形式，表达疑问的意思。
以下是对高中英语中情态动词及一般现在时的否定和疑问句的归纳总结：一、情态动词 (Modal Verbs) 的用法：1. 可能性 (Possibility)：- can- could- may- might2. 推测 (Speculation)：- must- should- may/might3. 必要性 (Necessity)：- must- have to- need to- should4. 动词表示能力 (Ability)：- can- could- be able to5. 动词表示许可 (Permission)：- can- could- may- might6. 动词表示请求 (Request)：- can- could- will7. 动词表示允诺 (Promise)：- will- shall- would8. 动词表示建议 (Advice)：- should- ought to- had better二、一般现在时的否定句 (Negative Sentences in Simple Present Tense)：1. 在一般现在时的肯定句中，在动词前加上助动词 "do" 或 "does"，并加上 "not" 以构成否定句。
情态动词用法归纳总结
情态动词用法辨析情态动词用法can could may might will would be able to shall should ought to must have to had better need dare表能力表请求表许可表意愿表建议表义务表推测表需求表敢不敢一、情态动词表能力时：1、can 和could二者的相似之处在于：二者皆可指因本身的特质或客观条件的存在，主语可能能够完成某事，强调的是主语具备某种能力，而非真实去执行某个动作。
二者的不同之处在于：can 对应现在或将来，而could 对应过去。
2、be able to 和couldcould 表示过去具备某种能力，强调再过去有完成某件事的可能性，而不一定真正去实行。
当be able to 应用于过去时，was/were able to 表示过去某次具体的行为，强调在过去成功完成了某事。
二、情态动词表请求时：1、此时could ，might ，would 并不表示过去，而是在语气上比原型更加委婉客气。
2、当用第一人称提出请求时，常用can/could 和may/might 。
相较而言，could 与may在表请求的问句中出现的频率最高；might表发请求的语气最为委婉客气，因此反而很少见；而can则常用于熟人间的对话中。
语气强度：can>could/might>might3、当用第二人称提出请求时，常用can/could和will/would。
其中could和would 表达请求的语气更委婉客气；而can与will则常用于熟人对话中。
语气强度：can/will>could/would三、情态动词表许可时：1、与表请求不同，will/would不论前接第几人称，都表示主语本身的意愿，无需得到他人的“许可”，所以will/would不可以用于表请求的句中。
2、can和may二者都可以表示对现在或将来动作的许可，其中can的使用频率更高。
情态动词的用法总结归纳表
情态动词的用法总结归纳一、情态动词的定义情态动词（Modal Verbs）用于表示说话人的态度和情感，如可能性、必要性、意愿、推测等。
它们不能独立作谓语，只能与其他动词原形构成谓语。
二、常见情态动词1.can (could) ：表示能力、可能性或允许。
2.may (might) ：表示许可、祝愿或推测。
3.must ：表示必须、义务或推测。
4.shall (should) ：表示命令、允诺、建议或推测。
5.will (would) ：表示意愿、将来或习惯。
三、情态动词的用法1.基本用法：情态动词+动词原形。
例如：He can swim.（他会游泳。
）2.情态动词无人称和数的变化，即情态动词第三人称单数不加-s。
例如：She may go.（她可以去。
）3.情态动词没有非谓语形式，即没有不定式、分词等形式。
4.情态动词后接动词原形，否定形式是在情态动词后加not。
例如：You mustn't smoke here.（你不可以在这里吸烟。
）5.带有情态动词的疑问句和否定句变换只需将情态动词提到主语前或直接在情态动词后加not。
例如：Can he dance?（他会跳舞吗？）He can't dance.（他不会跳舞。
）6.情态动词可以表示推测和可能性。
例如：It may rain tomorrow.（明天可能会下雨。
）7.情态动词可以表示命令和建议。
例如：You should study hard.（你应该努力学习。
）8.情态动词可以表示习惯和规律。
例如：He will arrive at nine.（他将在九点到达。
）9.情态动词可以与完成时连用，表示对过去的推测和猜测。
例如：She may have gone to the cinema.（她可能去看电影了。
）10.情态动词可以与进行时连用，表示对现在的推测和猜测。
例如：He must be studying in the classroom.（他一定在教室里学习。
情态动词高中知识点高三
情态动词高中知识点高三情态动词是一类具有特殊意义和用法的动词，它们在句子中一般与实义动词连用，表示说话人的推测、命令、请求、建议等情态。
在高中英语学习中，掌握情态动词的正确用法至关重要。
本文将介绍情态动词的相关知识点，帮助高三学生更好地运用这一语法现象。
一、情态动词的定义情态动词，又称情态助动词，是用来表示说话人对某种动作或状态的态度、推测、可能性、能力、意愿、义务等情态的一类特殊动词。
常见的情态动词包括can、could、may、might、must、shall、should、will、would等。
二、情态动词的用法1. 表示能力情态动词can表示某人具有能力或可能做某事，could用于过去说法。
例如：- She can speak three languages fluently.（她能说流利的三种语言）- He could lift the heavy boxes when he was younger.（他年轻时能搬起这些沉重的箱子）2. 表示推测和可能性情态动词may、might、could用于表示推测和可能性。
may用于表示较为肯定的推测，might和could表示推测的可能性较小。
例如：- The weather is cloudy, it may rain later.（天气多云，可能会下雨）- He might be late for the meeting.（他可能会迟到会议）3. 表示义务和建议情态动词must表示说话人对某种行为具有强烈的责任感或坚决要求，should表示建议。
例如：- We must obey the laws of the country.（我们必须遵守国家的法律）- You should apologize to your friend for your mistake.（你应该为你的错误向朋友道歉）4. 表示许可和请求情态动词can、may、could用于表示允许和请求。
情态动词知识点总结高中
情态动词知识点总结高中情态动词是英语中一个重要的语法现象，它们能够表达说话者的情感、态度、意愿等，以及表达说话者对事件的推测、猜测、可能性等。
了解情态动词的用法，能够帮助我们更准确地表达自己的意思，也有助于我们理解他人的意图。
本文将对情态动词的概念、用法、以及常见的情态动词进行总结和归纳，以便于读者更深入地理解情态动词的使用。
一、情态动词的概念情态动词（Modal Verb）是一类特殊的助动词，用来表示说话者的情感、态度、意愿等，以及表达说话者对事件的推测、猜测、可能性等。
情态动词通常用于句子的前面，后面跟动词原形，用来构成不同的语法结构和表达不同的含义。
英语中常见的情态动词有can、could、may、might、must、shall、should、will、would、ought to等。
这些情态动词具有一些共同的特点，比如不能独立完成谓语，后面必须跟动词原形；在疑问句和否定句中，情态动词的位置要发生变化等。
二、情态动词的用法1. 表示能力和可能性can与could表示说话者的能力或者对某种事情的可能性，其中can用于现在时，could用于过去时。
比如：I can speak Spanish.（我会说西班牙语。
）She could swim when she was five.（她五岁的时候就会游泳。
）may与might也表示可能性，may 用于现在时，might 用于过去时。
比如：It may rain tomorrow.（明天可能会下雨。
）I thought she might come.（我以为她可能会来。
）2. 表示请求和建议will与would可以表示请求，will用于肯定句，would用于否定句和疑问句。
比如：Will you please help me?（你能帮帮我吗？）I would like to go with you.（我想和你一起去。
）shall与should也可以表示请求或者建议，should更多地表示建议。
高中英语知识点归纳情态动词的用法与义项
高中英语知识点归纳情态动词的用法与义项情态动词是英语中一个重要的语法现象，是一种特殊的动词形式，用来表示说话人的态度、意愿、可能性、能力、推断等。
情态动词一般不能单独使用，而是与其他动词连用，构成动词词组来表示各种意义。
下面是对高中英语知识点归纳情态动词的用法与义项的总结。
一、情态动词的意义划分：1. 可能性（Possibility）情态动词：may, might, could, can用法：- may, might, could用于表示事情有可能发生或存在；- can主要用于表示某人具备某种能力。
示例：- It may rain tomorrow. (明天可能会下雨)- He might be at home. (他可能在家)- The key could be in the drawer. (钥匙可能在抽屉里)- I can speak Spanish. (我会说西班牙语)2. 动作愿望（Desire）情态动词：would like, want, wish用法：- would like用于表示客气地提出请求或愿望；- want用于表示强烈的需求或欲望；- wish用于表示遗憾或对现在情况的不满或希望。
示例：- I would like to have a cup of coffee. (我想来一杯咖啡)- She wants to go shopping. (她想去购物)- I wish I had more free time. (我希望我有更多的空闲时间) 3. 推测与推断（Speculation）情态动词：must, may, might用法：- must用于表示说话人根据某种依据做出肯定的推测； - may, might用于表示可能性的推测。
示例：- It must be raining outside. (外面肯定在下雨)- He may/might be busy right now. (他可能正忙)4. 动作能力（Ability）情态动词：can, could用法：- can表示某人具备某种能力；- could表示过去的能力或给予请求、许可的非正式方式。
高中英语语法——情态动词总结(附带练习)
情态动词总结I 情态动词的特征：1.本身有词义。
2.不能独立作谓语。
2. 后接动词原形一起构成谓语。
3. 不随人称和数的变化。
II 情态动词各自的基本意义及用法：1.大多数情态动词（除表‘能力、许可、意志’外），都可以表示推测，其程度有差异。
按可能性程度的高低排列为：must﹥will ﹥would ﹥ought to ﹥should完全肯定完全可能很可能﹥can ﹥could﹥may ﹥might可能有可能2. 区分情态动词的否定含义：may not或许不、可能不might not可能不can’t 不可能mustn’t不许、禁止shouldn’t不应该needn’t 不必1.情态动词表推测的反意疑问句，简单来说，就是以情态动词后的时态为淮，如句子里有明确的时间状语，则以其为准。
2.以must 为例：E.g. 1. You must be hungry now, aren’t you?2. He must be watching TV , isn’t he ?3 Tom must have lived her for a long time, hasn’t he ?4. She must have arrived yesterday, didn’t she?注：如选择题中（以She must have arrived yesterday, didn’t she？为例）既有didn’t she又有hasn’t she则以didn’t she？为最佳答案。
IV 情态动词专项练习与解析一( ) 1. You _____ return the book now. You can keep it till next week if you like.A. can’tB. mustn’tC. needn’tD. may not( ) 2. Where is my pen? I _____ it.A. might loseB. would have lostC. should have lostD. must have lost( ) 3. I wish I _____ you yesterday.A. seenB. did seeC. had seenD. were to see( ) 4. I didn’t hear the phone. I _____ asleep.A. must beB. must have beenC. should beD. should have been( ) 5. If my lawyer _____ here last Saturday, he _____ me from going.A. had been; would have preventedB. had been; would preventC. were; would preventD. were; would have prevented( ) 6. He _____ you more help, even though he was very busy.A. might have givenB. might haveC. may have givenD. may give( ) 7. If it _____ for the snow, we _____ the mountain yesterday.A. were not; could have climbedB. were not; could climbC. had not been; could have climbedD. had not been; could climb( ) 8. Without electricity human life _____ quite difficult today.A. isB. will beC. would have beenD. would be( ) 9. A computer _____ think for itself, it must be told what to do.A. can’tB. couldn’tC. may notD. might not( ) 10. Jenny _____ have kept her word. I wonder why she changed her mind.A. mustB. shouldC. needD. would( )11. We _____ last night, but we went to the concert instead.A. must have studiedB. might studyC. should have studiedD. would study( ) 12. — Could I borrow your dictionary?— Yes, of course you _____.A. mightB. willC. canD. should( ) 13. Tom ought not to _____ me your secret, but he meant no harm.A. have toldB. tellC. be tellingD. having told ( ) 14. — If he _____, he _____ that food.— Luckily he was sent to the hospital immediately.A. was warned; would not takeB. had been warned; would not have takenC. would be warned; had not takenD. would have been warned; had not taken ( ) 15. Peter _____ come with us tonig ht, but he isn’t very sure yet.A. mustB. mayC. canD. will( ) 16. I told Sally how to get here, but perhaps I _____ for her.A. had to write it outB. must have written it outC. should have written it outD. ought to write it out( ) 17. I didn’t see your sister at the meeting. If she _____, she would have met my brother.A. has comeB. did comeC. cameD. had come ( ) 18. — Shall I tell John about it?—No, you _____. I’ve told him already.A. needn’tB. wouldn’tC. mustn’tD. shouldn’t ( ) 19. When a pencil is partly in a glass of water, it looks as if it _____.A. breaksB. has brokenC. were brokenD. had been broken( ) 20. It’s nearly seven o’clock. Jack _____ be here at any moment.A. mustB. needC. shouldD. can( ) 21.— There were already five people in the car but they managed to take me as well.— It _____ a comfortable journey.A. can’t beB. shouldn’t beC. mustn’t have beenD. couldn’t have been ( ) 22. Johnny, you _____ play with the knife, you _____ hurt yourself.A. won’t; can’tB. mustn’t; mayC. shouldn’t; mustD. can’t; shouldn’t ( ) 23. The fire spread through the hotel very quickly but everyone _____ get out.A. had toB. wouldC. couldD. was able to ( ) 24. — When can I come for the photos? I need them tomorrow afternoon.— They _____ be ready by 12:00.A. canB. shouldC. mightD. need( ) 25. — I stayed at a hotel while in New York.— Oh, did you? You _____ with Barbara.A. could have stayedB. could stayC. would stayD. must have stayed ( ) 26. — Will you stay for lunch?— Sorry, _____. My brother is coming to see me.A. I mustn’tB. I can’tC. I needn’tD. I won’t( ) 27. — Are you coming to Jeff’s party?—I’m not sure. I _____ go to the concert instead.A. mustB. wouldC. shouldD. might( ) 28. — Write to me when you get home.— _____.A. I mustB. I shouldC. I willD. I can( ) 29. I was really anxious about you, you _____ home without a word.A. mustn’t leaveB. shouldn’t have leftC. couldn’t have leftD. needn’t leave( ) 30. — Is John coming by train?— He should, but he _____ not. He likes driving his car.A. mustB. canC. needD. may专项练习（二）1. I didn’t see her in the meeting room this morning. She _____ at the meeting.A. mustn’t have spokenB. shouldn’t have spokenC. needn’t have spokenD. couldn’t have spoken2. One ought _____ for what one hasn’t done.A. not to be punishedB. to not be punishedC. to not punishedD. not be punished3. If you really want yourself to be in good health, you must ___ always ___ so much.A. not; be smokingB. not; have smokedC. not; to smokeD. be not; smoking4. With so much work on hand, you _____ to see the game last night.A. mustn’t goB. shouldn’t goC. couldn’t have goneD. shouldn’t have gone5. Most of the students felt rather disappointed at the English party. They say that it ______ better organized.A. had beenB. had to beC. must have beenD. could have been6. I’m surprised that he _____ in the exam.A. should failB. would have failedC. may have failedD. should have failed7. The little girl _____ there alone.A. not dare goB. dares not goC. dare not goD. dare not to go8. “Must we do it now?” “No, you _____.”A. won’tB. needn’tC. can’tD. don’t9. He said he would rather not _____ it right now.A. doingB. to doC. doD. to be doing10. You _____ to the meeting this afternoon if you have something important to do.A. needn’t to comeB. don’t need comeC. don’t need comingD. needn’t come11. Put on more clothes. You _____ be feeling cold with only a shirt on.A. canB. couldC. wouldD. must12. I _____ play football than baseball.A. would ratherB. had betterC. like betterD. prefer13. I thought you _____ like something to read, so I have brought you some books.A. mayB. mightC. couldD. must14. There was plenty of times. She _____.A. mustn’t have hurriedB. couldn’t have hurriedC. must not hurryD. needn’t have hurried15. The plant is dead. I _____ it more water.A. will giveB. would have givenC. must giveD. should have given16. You _____ return the book now. You can keep it till next week if you like.A. can’tB. mustn’tC. needn’tD. may not17. It’s still early, you _____.A. mustn’t hurryB. wouldn’t hurryC. may not hurryD. don’t have to hurry18. Please open the window, _____?A. can’t youB. aren’t youC. do youD. will you19. We _____ for her because she never came.A. mustn’t have waitedB. shouldn’t have waitedC. mustn’t waitD. needn’t wait20. — May I stop here? — No, you _____.A. mustn’tB. might notC. needn’tD. won’t21. It’s a fine day. Let’s go fishing, _____.A. won’t weB. will weC. don’t weD. shall we22. I didn’t see her in the meeting room this morning. She _____ at the meeting.A. mustn’t have spokenB. shouldn’t have spokenC. needn’t have spokenD. couldn’t have spoken23. — Please don’t make a noise. — _____. I’ll be as quiet as a mouse.A. Yes, I won’tB. No, I won’tC. No, I willD. Yes, I will24. The young man has made so much noise that he _____ not have been allowed to attend the concert.A. couldB. mustC. wouldD. should25. — Where is John? — He _____ in the library.A. should beB. must beC. can beD. must have been26. Since the road is wet this morning, _____ last night.A. it must rainB. it must be rainingC. it must have rainedD. it must have been rain27. — Will your brother stay home tonight?— I’m not quite sure. He _____ to the cinema tonight.A. must goB. can goC. may goD. may be going28. She’s already two hours late. What ______ to her?A. can have happenedB. may have happenedC. should have happenedD. must happen29. You must be a writer, _____?A. mustn’t youB. are youC. must youD. aren’t you30. I got up early that morning, but I _____ so because I had no work to do.A. mustn’t have doneB. didn’t need to doC. needn’t have doneD. can’t have done31. He _____ have come here yesterday, but he didn’t.A. couldB. shouldC. ought toD. all the above32. I missed the last bus, so I _____ go home on foot.A. mustB. have toC. mayD. had to33. He ought to win the first prize, _____ he?A. oughtn’tB. shouldn’tC. mustn’tD. both A and B34. Everyone _____ do his best for the modernizations of our country.A. canB. mayC. shouldD. might35. Let’s clean our classroom, _____?A. will youB. don’t weC. shall weD. do you36. Let us play basketball, ______?A. will youB. don’t weC. shall weD. do you37. He asked me for this book many times. Please tell him that he _____ have it tomorrow.A. mustB. mayC. shallD. both B and C38. “Your phone number again? I _____ quite catch it.” “It’s 9568442.”A. didn’tB. couldn’tC. don’tD. can’t39. Mother _____ us stories when we were children.A. was used to tellB. is used to tellingC. used to tellD. used to telling40. She would rather _____ more money on books _____ on clothes.A. cos t … notB. to spare … don’tC. pay … thanD. spend … than专项练习（三）1. — Has Li Lin started? He said he would join in the party.— He ______. He is a man of keeping his word.A. could have leftB. must have leftC. can’t comeD. won’t be c oming2. — May I park my car here?— No, you ______. No car is allowed to park here.A. may notB. needn’tC. mustn’tD. daren’t3. — Excuse me, could you tell me where the Yajia Supermarket is?—It’s two blocks straight ahead. You ______ miss it.A. mustn’tB. can’tC. needn’tD. shouldn’t4. — I saw Mr. Sun at Tongyu Station this morning.—You ______. He’s still on holiday in Hawaii.A. couldn’t haveB. mustn’t haveC. shouldn’tD. needn’t5. — How about paying a visit to Dr. Wang, our former Chinese teacher?— Good idea. I will e-mail him today so that he ______ know ______ to expect us.A. shall; whyB. could; whenC. would; whatD. will; how6. Everything has two sides. Beautiful songs, sometimes, ______ be just noise to others.A. mustB. mayC. shouldD. could7. Someone ______ my umbrella. I found it wet yesterday.A. must be usingB. must have usedC. must useD. must have been using8. — How dangerous it was!— Yes, but for the passer-by’s quick action, th e girl ______.A. was drownedB. could have been drownedC. had drownedD. should be drowned9. You ______ scold such a pupil who always keeps silent so seriously that you ______ hurt him.A. should; canB. may; willC. mustn’t; mayD. can’t; must10. — Why does Alice know so much about Angkor Wat?— She ______ have been there, or ...A. mustB. oughtn’t toC. mayD. can’t11. —You may laugh, but I’ve been thinking of becoming a vegetarian.— Oh, you ______ be crazy. You will be hungry all the time.A. mustB. mayC. willD. need12. —What’s the matter with you?—Oh, I’m not feeling well in the stomach. I ______ so much fried fish just now.A. shouldn’t eatB. mustn’t have eatenC. shouldn’t have eatenD. mus tn’t eat13. — ______ he have been chosen as captain of the football team?— Yes, he ______.A. Can; must haveB. Must; must haveC. Can; mustD. Must; must14. Mr. Zhang ______ in Shanghai tomorrow morning.A. can have arrivedB. will have arrivedC. may have arrivedD. must have arrived15. Miss Wang started at 8 o’clock, and she ______ be there now.A. shouldB. canC. can’tD. need16. — It must be Mr. Li who did it. — No, it ______ be Mr. Li.A. mustn’tB. wouldn’tC. can’tD. may17. You ______ finish reading the book as soon as possible.A. mayB. canC. needD. should18. — Need you go to work now? — Yes, I ______.A. mustB. needC. canD. dare19. Your trousers are dirty. ______ them for you?A. Shall I washB. Will I washC. Am I going to washD. Am I washing情态动词专项练习与解析一【练习解析】1．C 从原题中You can keep it till next week if you like这一信息句可知，“你不必现在还”。
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高中英语语法总结大全之情态动词情态动词的语法特征1）情态动词不能表示正在发生或已经发生的事情，只表示期待或估计某事的发生。
2）情态动词除ought 和have 外，后面只能接不带to 的不定式。
3）情态动词没有人称，数的变化，即情态动词第三人称单数不加-s。
4）情态动词没有非谓语形式，即没有不定式，分词，等形式。
比较can 和be able to1）cancould 表示能力；可能 (过去时用could),只用于现在式和过去式(could)。
be able to可以用于各种时态。
They will be able to tell you the news soon. 他很快就能告诉你消息了。
2）只用be able toa. 位于助动词后。
b. 情态动词后。
c. 表示过去某时刻动作时。
d. 用于句首表示条件。
e. 表示成功地做了某事时，只能用was/were able to，不能用could。
He was able to flee Europe before the war broke out.= He managed to flee Europe before the war broke out.注意：could不表示时态1）提出委婉的请求，（注意在回答中不可用could）。
--- Could I have the television on?--- Yes, you can. / No, you can't.2）在否定，疑问句中表示推测或怀疑。
He couldn't be a bad man.他不大可能是坏人。
比较may和might1）表示允许或请求；表示没有把握的推测；may 放在句首，表示祝愿。
May God bless you!He might be at home.注意： might 表示推测时，不表示时态。
只是可能性比may 小。
2）成语： may/might as well，后面接不带to 的不定式，意为"不妨"。
If that is the case, we may as well try.典型例题Peter ___come with us tonight, but he isn't very sure yet.A. mustB. mayC. canD. will答案B. 表可能性只能用may.此句意可从后半句推出。
比较have to和must1)两词都是'必须'的意思，have to 表示客观的需要，must 表示说话人主观上的看法，既主观上的必要。
My brother was very ill, so I had to call the doctor in the middle of the night.我弟弟病得很厉害，我只得半夜里把医生请来。
(客观上需要做这件事)He said that they must work hard. 他说他们必须努力工作。
（主观上要做这件事）2)have to有人称、数、时态的变化，而must只有一种形式。
但must 可用于间接引语中表示过去的必要或义务。
He had to look after his sister yesterday.3）在否定结构中： don't have to表示"不必"mustn't表示"禁止"，You don't have to tell him about it.你不一定要把此事告诉他。
You mustn't tell him about it.你一定不要把这件事告诉他。
must表示推测1) must用在肯定句中表示较有把握的推测，意为"一定"。
2) must表对现在的状态或现在正发生的事情的推测时， must 后面通常接系动词be 的原形或行为动词的进行式。
You have worked hard all day.You must be tired.你辛苦干一整天，一定累了。
（对现在情况的推测判断）He must be working in his office. 他一定在办公室工作呢。
比较：He must be staying there.他现在肯定呆在那里。
He must stay there.他必须呆在那。
3) must 表示对已发生的事情的推测时，must 要接完成式。
I didn't hear the phone. I must have been asleep.我刚才没有听到电话，我想必是睡着了。
4) must表示对过去某时正发生的事情的推测，must 后面要接不定式的完成进行式。
---Why didn't you answer my phone call?---Well, I must have been sleeping, so I didn't hear it.5) 否定推测用can't。
If Tom didn't leave here until five o'clock, he can't be home yet.如果汤姆五点才离开这儿，他此时一定还未到家。
表示推测的用法can, could, may, might, must 皆可表示推测，其用法如下：1）情态动词+动词原形。
表示对现在或将来的情况的推测，此时动词通常为系动词。
I don't know where she is, she may be in Wuhan.2）情态动词+动词现在进行时。
表示对现在或将来正在进行的情况进行推测。
At this moment, our teacher must be correcting our exam papers.这时，我们老师想必在批改试卷。
3）情态动词+动词完成时。
表示对过去情况的推测。
We would have finished this work by the end of next December.明年十二月底前我们很可能已完成这项工作了。
The road is wet. It must have rained last night.地是湿的，昨天晚上一定下雨了。
4）情态动词+动词的现在完成进行时。
表示对过去正在发生事情的推测。
Your mother must have been looking for you.你妈妈一定一直在找你。
5）推测的否定形式，疑问形式用can't, couldn't表示。
Mike can't have found his car, for he came to work by bus this morning.迈克一定还没有找回他的车，因为早上他是坐公共汽车来上班的。
注意：could, might表示推测时不表示时态，其推测的程度不如can, may。
情态动词+have+过去分词1) may(might) have + done sth, can (could) have + done sth表示过去，推测过去时间里可能发生的事情。
Philip may (might) have been hurt seriously in the car accident.Philip can (could) have been hurt seriously in the car accident.2)must have +done sth，对过去时间里可能发生的事情的推测，语气较强，具有"肯定"，"谅必"的意思。
---Linda has gone to work, but her bicycle is still here.---She must have gone by bus.3) ought to have done sth, should have done sth本应该做某事，而事实上并没有做。
否定句表示"不该做某事而做了"。
You ought to (should) have been more careful in this experiment.He ought not to have thrown the old clothes away.（事实上已扔了。
）ought to 在语气上比should 要强。
4) needn't have done sth本没必要做某事I dressed very warmly for the trip, but Ineedn't have done so. The weather was hot.5) would like to have done sth本打算做某事I would like to have read the article, but I was very busy then.should和ought toshould 和ought to 都为"应该"的意思，可用于各种人称。
---Ought he to go?---Yes. I think he ought to.表示要求，命令时，语气由 should（应该）、had better最好）、must（必须）渐强。
had better表示最好had better 相当于一个助动词，它只有一种形式，它后面要跟动词原形。
had better do sthhad better not do sthIt is pretty cold. You'd better put on my coat.She'd better not play with the dog.had better have done sth表示与事实相反的结果，意为"本来最好"。
You had better have come earlier.would rather表示"宁愿"would rather dowould rather not dowould rather… than…宁愿……而不愿。
还有would sooner, had rather, had sooner都表示"宁愿"、"宁可"的意思。
If I have a choice, I had sooner not continue my studies at this school.I would rather stay here than go home. = I would stay here rather than go home.典型例题----Shall we go skating or stay at home?----Which ___ do?A. do you ratherB. would you ratherC. will you ratherD. should you rather答案B。