高中英语语法情态动词教学案
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
英语高考专题复习讲与练15
情态动词
一、考点聚焦
1、情态动词的基本用法
(1)can、be able to 和could
①can和be able to 都表示能力,意思上没多大区别。但can只有现在和过去时,而be able to 则有更多的形式。但当成功地完成某一具体动作时,通常不用could 而用was/were able to 来表示。这时was/were able to 相当于managed to,表示经过一番努力,终于能够完成某事。如:Can you use chopsticks?
The wounded man still was able to get to the village and was saved in the end.
②can 和could
can 和could 都可以表示能力、技能、许可、建议或请求和可能性。但比较委婉客气地提出问题或陈述看法,一般用could,回答时则用can。如:
Could you help me carry the bag?
Can I help you?
(2)may/might
①may/might 表示可能,但may 比might 可能性大。如:-Why isn' t he in class?
He may be sick.(生病的可能性较大)
He might be sick.(生病的可能性较小)
②may/might 表示“允许”,may 用于现在时或将来时,might 常用在间接引语中表过去时,但might 也可用于现在时间,表示比较委婉的语气,回答用may 。如:
He says we may leave.
He said we might leave.
③may / might 表示建议或请求,但might 比may 更客气,意思更肯定而无过去时态的
含义。
Yes, you can / may.
—May / Might I use your bike?
No, you mustn 't
3) must
①must 表示必须,应该,没有时态变化。如:
You must do everything as I do. ②must 表示肯定的推测。如:
The light is still on, so he must be at home.
③mustn't 表示禁止做某事。如:
You mustn ' t smoke in the office.
(4)have to
have to 表示“必须、不得不”,是由于某种外界(客观)原因而“必须”,“不得不”做某事,也可表示经常的或习惯性的事“必须”做。have to 的否定形式表示不必。have to 可用于多种时态中。如:
You will have to clean your own boots when you join the army.
I have to be at my office every evening.
(5)should / ought to
①should和ought to 表示应当、应该,前者比后者语气轻。如:You should / ought to work hard.
②should / ought to work hard.
Since she is not here, whe should / ought to be in the classroom.
③should / ought to 的否定形式表示禁止之意。如:Children shouldn ' t smoke.
④should 可表示陈述意见,推出建议或请求;而ought to 可以表示劝告之意。如:
You ought to respect your parents.
He suggested that they should leave at once.
(6)will / would
① will 用于各种人称表示“意志”、“意愿”或“决心”等,否定式won' t + 动词。如:I
will tell you all about it.
Tom won't do usch a thing.
②will 用于疑问句中,常用在第二称时表示说话人向对方提出“请求”或“询问”如:
Will you please tell her the news when you see her?
③will 表示习惯性的动作,有“总是”、“惯于”的含义。如:Fish will die out of water.
④would 表示客气的请求、建议或意愿。如:Would you please be quiet?
Would you like coffee?
⑤would 表示过去反复发生的动作。如:
When I passed my school I would see my teachers who taught me 5 years ago.
(7)need
need 作“必要”讲,既可作情态动词,也可作实义动词。作实义动词时后面的动词不定式要带
to,其变化与一般动词相同。如:
I need to think it over.
—Need you go now? —Yes, I must./No, I needn ' t
(8)dare
dare表示“敢”的意思。作为情态动词时,主要用在疑问句和否定句中。dare若作实义动
词,后面可带to 的不定式,此时to 也可以省略。dare 与need的用法相似。如:
How dare you say that?
She doesn ' t date(to)ask her father.
(9)used to
used to 表示过去常常发生的动作或存在的习惯,但现在已不复存在了。如:He used to smoke.
(10)shall
①shall 作为情态动词用于第二、三人称,表示说话人的意愿,有“命令”、“警告、威胁、
强制”和“允许”等意思。如:
We shall do as our teacher says.
You shall have the book as soon as I finish it.
②在疑问句中,shall 用于征求对方的意见或请求指示,常用于第一、第三人称。如:Where shall he
wait for us?
Shall we go out for a walk?
2、情态动词表示推测或判断的用法下表即是表示推测的情态动词使用的场合: