1、情态动词情态动词用法用法对应的意思对应的意思can and could 1.表示能力表示能力能能2.表猜测（疑问或表猜测（疑问或否定句）否定句）不可能不可能3.表许可或者请求表许可或者请求许可许可可以可以may and might1.表许可或者请表许可或者请求许可求许可可以可以2.表可能性表可能性可能可能3.表祝愿表祝愿祝祝情态情态动词动词用法用法对应的意思对应的意思 must1.表示必要性表示必要性必须必须2.表推测（肯定句）表推测（肯定句）一定，肯定一定，肯定3.表不可为而为表不可为而为偏偏，偏要偏偏，偏要4.表示禁止表示禁止不许，不准，不可以不许，不准，不可以shall1.二，三人称，表
2、二，三人称，表命令，允诺，警告等命令，允诺，警告等2.一，三人称问句一，三人称问句中，表征求对方意见中，表征求对方意见3.第一人称，表将第一人称，表将来来情态动词情态动词用法用法对应的意思对应的意思should1.表示应当表示应当应当，应该应当，应该2.表示推测表示推测（按道理按计划）（按道理按计划）应该会应该会will1.表示愿望，计划表示愿望，计划 将将2.表示倾向或者习表示倾向或者习惯性动作惯性动作会会3.表请求，询问表请求，询问请请好吗？好吗？would1.过去曾有的过去曾有的要，会，将要，会，将2.委婉请求，看法委婉请求，看法 请请好吗？好吗？Find the sentences c
3、ontaining modal verbs in the reading passage.Then by lunchtime they would all be sold.What could have happened?Nothing could be better.Something terrible must have happened if Li Chang was not to coming to eat in his restaurant as he always did.He could not believe his eyes.Perhaps he should go to t
4、he library and find out.He had better do some research!Even though her customers might get thin after eating Yong Huis food,They would become tired very quickly.1.should和和ought toa.should,ought to都可表示都可表示“应该应该”。ought to用于用于表示按道理应当表示按道理应当，常指，常指客客观的义务或责任观的义务或责任，大多数情况下可用大多数情况下可用should代替，但比代替，但比should语气
5、重语气重。I should help her because she is in trouble.You ought to take care of the baby.b.表示劝告、建议或命令时，表示劝告、建议或命令时，should 和和ought to可通用可通用，但在，但在疑问句中常用疑问句中常用should。ought to的否定式为的否定式为oughtnt to 或或 ought not to。You should/ought to go to class right away._ I open the window?What should we do next?ShouldYou _
6、(ought to)leave in such a hurry.你不应该离开的这么匆忙。你不应该离开的这么匆忙。oughtnt/ought not toc.should,ought to 都可表示推测。都可表示推测。He ought to/should be home by now.This is where the oil ought to/should be.should和和ought to后面跟动词不定式的完成后面跟动词不定式的完成式式,其肯定句表示其肯定句表示“过去应该做而未做过去应该做而未做”,其否定句则表示其否定句则表示“过去不该做但做了过去不该做但做了”。You _ the de
7、cision a week ago.你应该在一周前就做决定。你应该在一周前就做决定。I _ such a foolish mistake.我不应该犯这样愚蠢的错误。我不应该犯这样愚蠢的错误。多数情况下，多数情况下，ought to可与可与should互换使互换使用。用。ought to的反意疑问句用的反意疑问句用shouldnt替替代。代。should/ought to have madeshouldnt have madeYou ought to have helped him with his English,_?A.wont you B.ought not youC.shouldnt y
8、ouD.wouldnt you2.must和和have tomust 的用法的用法 1)表示主观的义务和必要表示主观的义务和必要,主要用于肯定主要用于肯定句和疑问句句和疑问句,意思为意思为“必须必须，得得，要，要”；由；由must引起的疑问引起的疑问句，句，肯定回答肯定回答要用要用must或或 have to,否否定回答定回答要用要用neednt 或或 dont have to,意意思是思是“不必不必”；must的否定形式的否定形式mustnt表示禁止，意思表示禁止，意思是是“不能，不许不能，不许”。如：。如：Must I finish the task right now?我现在必须完成这个
9、工作吗？我现在必须完成这个工作吗？Yes,you must./Yes,you have to.是的。是的。(No,you _./No,you dont have to.不，不必。不，不必。)You mustnt come here without permission.未经允许，你不能来这儿。未经允许，你不能来这儿。neednt have to的用法的用法 1)must表示一种主观的需要，而表示一种主观的需要，而have to 表表示一种客观的需要，意思是示一种客观的需要，意思是“不得不不得不”。如：如：I have to attend an important meeting this af
10、ternoon.今天下午我不得不参加一个重要的会议。今天下午我不得不参加一个重要的会议。Mother is out,so I have to look after the shop.妈妈不在家，因此我不得不照看商店。妈妈不在家，因此我不得不照看商店。2)have to的否定形式是的否定形式是 dont have to,相相当于当于 neednt。如：如：They dont have to buy a computer at present.他们目前没有必要买电脑。他们目前没有必要买电脑。have to的第三人称单数形式是的第三人称单数形式是has to，一，一般过去式是般过去式是had to，
11、一般将来式是，一般将来式是will have to。Li Hua has to pass an examination before he can start work.My car was broken,so I had to walk home.Itll have to be on a Sunday.Ill be working every other day.The boss has given everyone a special holiday,so we _ go to work tomorrow.A.cant B.mustntC.neednt D.shouldnt【点拨点拨】考查
12、情态动词。根据题意考查情态动词。根据题意,可知可知这里表示这里表示“没有必要没有必要”,故只能选故只能选C项。项。What do you think we can do for our aged parents?You _ do anything except to be with them and be yourself.A.dont have to B.oughtnt toC.mustnt D.cant【点拨点拨】根据题意根据题意“除了和他们呆在一除了和他们呆在一起做你自己外起做你自己外,没有必要做任何事情。没有必要做任何事情。”可知这里选择可知这里选择dont have to表示表示“不
13、必不必”。故选故选A项。项。3.must和和needa.need作情态动词时作情态动词时,只能用于疑问句只能用于疑问句和否定句。构成否定句和疑问句时不和否定句。构成否定句和疑问句时不借助于助动词借助于助动词do。Need I finish the work today?Yes,you must./No,you neednt.b.need 也可做实义动词，常用于下列句式：也可做实义动词，常用于下列句式：1.主语（主语（sb）need to do sth.2.主语（主语（sth）need to be done/doing3.主语主语 need+n.You need _(know)your own
14、weakness and strength.The cucumbers and mushrooms need _(cut)up to make dumplings.I need some _（醋）（醋）.to knowvinegarto be cut/cutting情态动词情态动词用法用法ought/oughtnt to 按道理应当，常指客观的义务按道理应当，常指客观的义务和责任和责任should/shouldnt 劝告，建议，命令劝告，建议，命令mustnt禁止，严禁禁止，严禁neednt不必，没有必要不必，没有必要(dont)have to不得不，强调客观需要不得不，强调客观需要will将
15、，会，将，会，请请好吗？好吗？can/cant能力，许可，否定疑问表推测能力，许可，否定疑问表推测Choose suitable modal verbs below to complete the following dialogues.ought/oughtnt to should/shouldnt willmustnt neednt (dont)have to can/cant1.Sam:How can I grow thinner,Mum?Mum:Well,you _ eat food with plenty of fibre that helps you digest better.A
16、nd you _ stop drinking cola or eating sweet food.have to should Sam:Does it mean I _ eat my favourite fried chicken any more?Mum:Not exactly,if you love fried chicken,you _ give it up.Just eat it less often.You _ worry too much:a little fried chicken _ do you good!shouldnt needntdont have to/neednt/
17、shouldnt will2.Doctor:You are sick because youve eaten poisonous mushrooms.Where did you get them?Lucy:I picked them in the forest.I know we _ eat fresh vegetables.Doctor:Oh,but you _ eat them until youre sure they are not poisonous.Lucy:Thank you,doctor.Ill be more careful next time.have tomustnt 3.Charles:I wish I could see things clearly in the dark.Tom:Eating carrots _ help you see better.You _ eat some every day.ought to shouldHomework 1.学案学案page 22，语法冲关。，语法冲关。2.学案学案page28，完型填空，完型填空
