情态动词
情态动词可以理解为表达情感和态度的词，所以表达“情态”，就要用到咱们常见的情态动词can / could /may / must / will / would / shall / should / dare/ need / had better / used to等，下面我们一起复习一下吧！
01
can/may/must的否定回答
肯定回答用本身，否定回答注意红色字体
1.--May I do sth.? --No, you mustn’t.
2.--Can I do sth.? --No, you can’t.
3.--Must I do sth.?
--No, you needn’t. / don’t have to.
may---mustn’t ; can---can’t ; must---needn’t
02
重点情态动词的用法
No.1
can/could
①表能力 , 意为“能;会”; can't意为“不能;不会”
can/could=be able to【将来时和完成时只能用be able to】
be able to 用于表示经过努力而成功地办成某事，相当于succeed in/manage to do, 此时不能can.
e.g.His mother couldn’t afford to pay for her child’s education.
=His mother wasn’t able toafford to pay for her child’s education.
②表请求允许 意为“可以”,此时could比can语气更委婉,更客气,不要理解为是can的过去式。
could一般用于疑问句中,回答时可用can.礼貌用语“Could you please...”中的please可以放在句尾。
e.g.--Could you please take out the rubbish?--Yes, sure.(=Yes, I can.)
e.g.--Could we get something to drink after movie?--No, you can’t.
③表示可能性,常用于疑问句和否定句中，指“某事是否是事实”。【简单了解】
e.g.Can the story be true?这个故事可能是真的吗？
④表推测，多用于否定推测，can’t be/couldn't be一定不是，此时could不表示时态，只表示可能性比can小。即can>could(可能性)
e.g.What she says can’t be true.她说的一定不是真的【肯定推测What she says must be true.】
A.现在的推测
肯定推测:must be（状态）/must do(动作)
[must be doing对正在进行或将来的推测]
否定推测:can’t be[can’t be doing]
B.过去的推测
肯定推测:must have done
否定推测:can’t have done/couldn’t have done（可能性小）
⑤can not, could not与比较级连用，表示最高级的含义。
e.g.I can’t agree with you more.我非常同意你的看法。
⑥惯用句型及短语
can’t stand it (to do sth.)不能容忍...【=I can’t bear it=I can’t put up with it.】
can’t afford to do sth.不能承受....
e.g.We can’t afford to wait any longer to take action!
can’t help doing sth.情不自禁做...can’t help to do sth.不能帮助做...
e.g.She can’t help to clean the house because she’s busy making a cake.
e.g.I couldn’t help crying when I saw him at the airport.
can’t wait to do sth. 迫不及待做...
e.g.My sister can’t wait to go camping with her family.
as...as+主语+can/could尽可能...
e.g.You should speak English as much as you can.
can not...too.../enough怎么做都不过分
e.g.You cannot be too careful.你越仔细越好。
No.2
may
①表允许，许可，意为“可以”，疑问句中might>may(语气委婉程度)
e.g.May I take your order?
②表推测:may>might,could>might(可能性比较)
注意 may be &maybe 区别
e.g.All of these birthday foods may be different, but the ideas are the same.【may (be)为情态动词】
e.g.Maybe their ideas are the same.【maybe为副词=perhaps】
e.g.He was really worried about that his coach might kick him off the team.
注意can:表示一般的可能性或理论上的；may表示实际发生的可能性
e.g.I can take a bus to school, but I may walk tomorrow.
③表示祝愿May+主语+动词原形 【一般了解】
e.g.May all your dreams come true.愿你梦想成真。
④may/might as well+动词原形 意为“还是...好，最好”【一般了解】
e.g.We may as well stay where we are.我们还是留在现在的地方为好。
No.3
must
①表主观意愿；意为“必须，一定”(别无选择)，mustn't表示“禁止，不允许”
e.g.We must be on time for class.
e.g.We must not take photos in the museum.
e.g.--Must I finish my homework now?--No, you needn’t./No,you don’t have to.【否定回答是考点】
③must&have to区别
e.g.Jim must work hard at English this term.【must侧重说话人的主观意志】
e.g.I have to finish reading a book and give a report next Monday.【have/has to 侧重客观需要】
e.g.Will we have to move to other planets?
have/has to可用于多个时态如had to/will have to等
No.4
shall/should
should的用法
①shall的过去式，间接引语
e.g.She said she should not let her mum down.
②表义务，责任，意为“应该，应当”=ought to= be supposed to【should侧重主观性】
ought to意为“应该，应当”，表示责任、义务、劝告时语气比should强,侧重客观性
否定ought not to/oughtn’t
e.g.Humans ought to stop polluting nature.【责任】
③表建议，意为“应该”>had better【建议的程度】
e.g.Everyone should play a part in saving the earth.
④表推测，意为“可能，该”
e.g.He should be home at the moment.【简单了解】
⑤should have done“过去本该做而没有做”【简单了解】=ought to have done
e.g.You should have finished your homework yesterday, but you didn’t.
shall的用法【简单了解】
①与第一人称I/we合用，表示将；会
e.g.I shall not let you down,mum.
②征求对方意见或请求，用于一、三人称的疑问句中。
e.g.Shall we go fishing this week?
③表警告，命令，威胁，许诺，决心，用于二、三人称。
e.g.You shall be fined if you park your car here.
④表义务或规定，用于第三人称。
e.g.Students shall wear school uniforms on weekdays.
⑤表示应该，可能，用于预测，常用于第二、三人称的肯定句。
e.g.You shall stay here with us this time.
No.5
will/would
will的用法
①表意愿,决心，意为“要，愿意”
e.g.I will help you at any time.
②回答请求、命令的句子，肯定用will，否定用won't
e.g.--Please remember to take an umbrella with you.--OK, I will.
e.g.--Never touch my books while I am away.
--I won’t.
③与第二人称连用，用于疑问句中，表示“邀请，请求”
e.g.Will you please turn down the TV?【请求】
④反义疑问句（祈使句） Come here tomorrow, will you?
would的用法
①与第二人称连用，用于疑问句中，表请求或要求，比will委婉。
e.g.Would you tell me the way to the airport?
e.g.--Would you like to have a cup of tea?
--Yes, I’d love to./No, thanks.
②would rather do sth. (than do)宁愿做...
e.g.I would rather stay here (than go out).
No.6
need
①意为“需要”，否定needn't 意为“不必”=don’t/doesn’t/didn’t have to
②作为实义动词时，否定don’t / doesn’t need to
need to do sth.需要做某事 【主动】
e.g.You need to eat more vegetables.
need doing sth.=need to be done【被动】
e.g.Those flowers need watering.
③in need= in trouble 在困难的时候
④There is no need (for sb.) to do sth.没有必要做某事
e.g.There is no need for us to tell her the news.
No.7
dare
①情态动词 dare do sth./否定daren’t do sth.
e.g.She dare say what she thinks.【情态动词】
②实义动词dare to do sth.否疑答用助动词do/does/did
e.g.She dares to say what she thinks.【实义动词】
e.g.She doesn’t dare to say what she thinks.【否定】
e.g.Does she dare to say what she thinks?【疑问】
③How dare you/he...?表示“愤怒，谴责”
e.g.How dare you say that?
No.8
had better
① had better do sth.最好做某事
②had better not do sth.最好不要做某事
No.9
used to【重点】
【否定used not to/ didn’t use to】
①used to do过去常常做某事
e.g.We used to work more than ten hours a day.
②be/become/get used to doing sth.习惯做某事
e.g.Jason is used to staying up late.
③be used to do/for 被用来做某事
e.g.Wood is used to make paper.
e.g.Wood is used for making paper.
03
情态动词表推测
推测语气：must > can > could > may > might
肯定推测
1.现在 must +be/do一定是..
2.正在进行/将来 must be doing一定正在做..
3.过去 must have done想必,准是做过...
否定推测
1.现在 can't be 不可能/一定没有....
2.正在进行/将来 can't be doing一定没在做...
3.过去 can’t have done一定没有做过/不可能做过..
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