内容正文:
情态动词
《英语 基础模块1》(外研版2021版)
Unit 7 When Disaster Strikes 语法
Lead
in
目录
04 特殊用法对比
03 常见的情态动词用法
01 情态动词概念
02 常见类型
07 检测练习
08 知识小复盘:重点速记卡
05 其他情态动词
06 情态动词问答
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(动画)用祈使句发出指令或表达禁止
(动画)区别“祈使句+and+陈述句”和“祈使句+or+陈述句”
3
01
情态动词概念
情态动词概念
定义
情态动词表示说话人的语气、态度或推测。
它们赋予句子“可能性”、“必要性”、“许可”、“意愿”、“能力”等情感和语气色彩。
e.g.
You should get more rest when you‘re sick.(建议)
You may submit the report by Friday.(许可)
情态动词的统一特点
1. 后面接动词原形
2. 无人称和数的变化
3. 不能单独作谓语
4. 否定再其后+not
正确:He can swim. (√)
错误:He can to swim. (×)
He can swims. (×)
否定句:You should not smoke here. (在情态动词后加not)
02
常见类型
情态动词常见类型
功能类别 核心含义 情态动词
能力 表示能够做某事 can, could
许可 表示允许或请求允许 can, may, could, might
义务/必要 表示必须或应该做某事 must, have to, should, ought to
推测/可能性 表示对情况的猜测或判断 must, will/would, may/might/could, can‘t/couldn’t
建议 提出建议或劝告 should, ought to, could, might
意愿/请求 表达意愿或礼貌请求 will, would, can/could
习惯 描述过去的习惯或状态 would, used to
承诺/威胁 表示承诺或警告 shall, will
常见情态动词否定形式
肯定形式 否定形式 缩略否定
can can not can't
could could not couldn't
may may not (无缩略)
might might not mightn't
must must not mustn't
should should not shouldn't
will will not won't
would would not wouldn't
03
常见的情态动词用法
一、can / could
1. 表示能力
can (现在能力)
could (过去能力)
e.g.
I can swim very well.
我游泳游得很好。
When I was young, I could run 5 kilometers without stopping.
我年轻时能一口气跑5公里。
一、can / could
2. 表示许可
can (非正式许可)
could (更礼貌的请求)
e.g.
Can I use your phone?
我能用一下你的手机吗?
Could I borrow your pen for a moment?
我可以借一下你的笔吗?
一、can / could
3. 表示可能性
can (理论可能性)
could (较小可能性)
e.g.
It can get very cold here in winter.
这里的冬天可能会很冷。
He could be in his office now.
他现在可能在他的办公室。
二、may / might
1. 表示许可
may (正式许可)
e.g.
You may begin the examination now.
你现在可以开始考试了。
May I ask you a question?
我可以问您一个问题吗?
二、may / might
2. must表示可能性
may (约50%可能性)
might (约30%可能性,更不确定)
e.g.
I may go to the party tonight.
我今晚可能去参加派对。
She might not come to the meeting.
她可能不来开会。
三、must / mustn't
1.must 表示义务/必须
e.g.
We must obey the law.
我们必须遵守法律。
You must finish your homework before watching TV.
你必须做完作业才能看电视。
三、must / mustn't
2. 表示肯定推测
e.g.
He must be tired after working all day.
工作了一整天,他一定累了。
They must have left already. The house is dark.
他们一定已经离开了。房子是暗的。
三、must / mustn't
3. mustn't 表示禁止
e.g.
You mustn't smoke here.
你绝不能在这里吸烟。
Students mustn't use mobile phones during the exam.
考试期间学生禁止使用手机。
表示建议/应该
should (常用)
ought to (稍正式,强调责任)
01
You should see a doctor about that cough.
你的咳嗽应该去看看医生。
You ought to apologize for what you said.
你应该为你说的话道歉。
四、should / ought to
表示推测
02
They should arrive by 6 o'clock.
他们应该在6点前到达。
This book should be helpful for your research.
这本书应该对你的研究有帮助。
四、should / ought to
will 表示意愿/打算
01
I will help you with your project.
我会帮你完成项目。
She will call you tomorrow.
她明天会给你打电话。
五、will / would
will 表示预测
02
It will rain this afternoon.
今天下午会下雨。
He will probably be late.
他可能会迟到。
五、will / would
would 表示礼貌请求
03
Would you please close the window?
请关上窗户好吗?
Would you mind waiting for a moment?
您介意稍等一会儿吗?
五、will / would
would 表示过去习惯
04
When I was a child, I would visit my grandparents every weekend.
小时候,我每个周末都会去看望祖父母。
五、will / would
1. 表示客观必要
I have to go now. It's getting late.
我得走了。时间不早了。
Do you have to work on weekends?
你周末必须工作吗?
六、have to / have got to
2. had to 表示过去必须
Yesterday I had to finish the report.
昨天我必须完成报告。
We had to wait for two hours.
我们不得不等了两个小时。
六、have to / have got to
特殊用法对比
04
1. must vs. have to
must (主观认为必须)
have to (客观要求必须)
e.g.
I must exercise more. (我自己觉得需要)
我必须多锻炼。
I have to attend the meeting. (老板要求/规定)
我必须参加这个会议。
特殊用法对比
2. can't vs. mustn't
can't (表示能力不足或不允许)
mustn't (强烈禁止)
e.g.
I can't swim. (能力)
我不会游泳。
You mustn't tell anyone this secret.
你绝不能把这个秘密告诉任何人。
特殊用法对比
05
其他情态动词
作情态动词
表示需要,主要用于否定或疑问句,否定形式为needn't,表示“不必”
注意:用need 提问时,肯定回答为must,否定回答为needn't或don't have to.
☆ Need I stay here any longer?
我需要继续诗在这儿吗?
-Yes, you must. /No, you needn'./don't have to.
一、need
作实意动词
need可以作实义动词,此时有人称和时态的变化
◆如果是人作主语,后面接to do.
☆ She needs to do itright now.她需要马上去做。
◆如果物作主语,一般后面接doing或to be done 主动形式的动名词doing,具有被动意义。
☆The door needs painting = The door needs to be painted.
这扇门需要被上漆。
一、need
二、dear(用法跟need相似)
作为情态动词,多用于否定/疑问句或条件句中,无人称变化,只有一般现在式和一般过去式,意为“敢”。
☆I daren’t ask him.我不敢问他。
作情态动词
06
情态动词问答
考点一:must
. 问句 Must I...?
肯定回答 Yes, you must.
否定回答 No, you needn't. /No, you don't have to.
注意:
Must 的否定式 mustn't 表示“禁止”,不是“不必”。
must 提问的回答
考点二:need
. 问句 Need I...?
肯定回答 Yes, you must.
否定回答 No, you needn't.
need 提问的回答
07
检测练习
一、单项选择
从A、B、C三个选项中选择最佳答案,填入题前括号内。
1. You _______ smoke here. It's a gas station.
A. needn't B. mustn't C. don't have to D. may not
2. — Must I finish the work today?
— No, you _______. You can do it tomorrow.
A. mustn't B. can't C. needn't D. shouldn't
3. She _______ speak three languages: English, French and Chinese.
A. may B. must C. can D. need
4. — _______ I borrow your dictionary?
— Of course you can. Here you are.
A. Must B. Need C. Should D. May
5. He _______ be at home. The light is on.
A. can B. might C. must D. need
一、单项选择
6. You look pale. You _______ see a doctor.
A. would B. should C. could D. might
7. — Need I wait for you after school?
— Yes, you _______.
A. need B. must C. can D. may
8. When I was young, I _______ run very fast.
A. can B. may C. could D. might
9. The baby is sleeping. You _______ make so much noise.
A. needn't B. don't have to C. mustn't D. couldn't
10. — _______ you pass me the salt, please?
— Sure, here you are.
A. Must B. Need C. Should D. Could
答案解析:
1. B. mustn't
解析:加油站是严禁吸烟的场所,mustn't表示“禁止”、“绝对不可以”,符合语境。needn't和don't have to都表示“不必”,语气太弱;may not表示“可能不”或“不被允许”,但在此处mustn't更符合禁止的强烈语气。
2. C. needn't
解析:Must I...?的否定回答不能用mustn't(那是“禁止”的意思),而要用needn't或don't have to,表示“不必”。本题中You can do it tomorrow提示不需要今天完成,因此用needn't。
3. C. can
解析:句子表达的是她“能够”说三种语言,这是能力,因此用can。may表示许可或可能,must表示必须或肯定推测,need表示需要,均不符合语境。
4. D. May
解析:May I...?是请求许可的正式表达,答句中的can也印证了这是许可类问句。Must表示必须,Need表示需要,Should表示应该,都不适合用于请求借用物品。
5. C. must
解析:灯亮着,说明他“一定”在家。must表示肯定推测,语气最强。might也表示推测,但语气较弱(“可能”),与灯亮着这一确凿证据不符。
答案解析:
6. B. should
解析:脸色苍白,说话人给出建议“应该”去看医生。should表示建议或劝告。could和might也可以表示建议,但语气更委婉;would通常表示意愿或习惯。
7. B. must
解析:Need I...?是情态动词need开头的疑问句,其肯定回答要用must,不能用need。这是固定搭配,需要特别记忆。
8. C. could
解析:时间状语When I was young表示过去,因此要用过去式could表示过去的能力。can是现在式,may和might表示许可或可能,都不符合时间要求。
9. C. mustn't
解析:宝宝在睡觉,所以“禁止”大声喧哗。mustn't表示禁止。needn't和don't have to都表示“不必”,意思是你可以选择不做,但这里是不允许做,语气完全不同。
10. D. Could
解析:Could you...?是表示礼貌请求的常用句型,比Can you...?更委婉客气。答句Sure, here you are表明这是一个请求帮助的语境。
06 知识小复盘:重点速记卡
情态动词
基本概念
用法
类型
问答
THANKS
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