高中英语外研版 (2019)选择性必修 第四册Unit 6 Space and beyond教课内容ppt课件

情态动词

一、情态动词的基本用法(1)

[观察例句]

1．The police still have not found the lost child，but they are doing all they can.

2．Our daughter could walk when she was nine months old.

3．Accidents can happen on such rainy days.

4．We may go to the cinema tonight，but we are not sure yet.

5．That might be our taxi but I doubt it.

6．I could do it now，if you like.

7．Must I give up smoking?

8．Did she have to pay a fine?

[归纳用法]

1．表示能力：(1)can 表示现在的能力(如例1)；(2)could表示过去的能力(如例2)。

2．表示推测：推测即可能性(如例3－例6)。

3．表示必要性：(1)must表示主观上的必要性(如例7)；(2)have to表示客观上的必要性(如例8)。

[名师点津]

表示推测的情态动词的用法比较(由强到弱)：

[即学即练1]　用适当的情态动词填空

①An experienced teacher can also make mistakes.

②You can't mistake their car；It has got a bright red line all over it.

③He must be the wanted man.He's exactly like the one in this picture.

④I can run faster than you.

⑤The question was so hard that he could not answer it.

⑥I have to go to the dentist tomorrow.

二、 情态动词的基本用法(2)

[观察例句]

1．What shall we do this weekend?

2．The candidates shall remain in their seats until all the papers have been collected.

3．He should be here on time － he started early enough.

4．You can stay here as long as you can，if you will.

5．She will listen to records alone in her room for hours.

6．When he was abroad，he would read as many books as possible.

7．I didn't know whether he dared say that to him.

8．If she wants anything，she need only ask.

[归纳用法]

1．shall表示征求意见(如例1)和宣布法律、规定(如例2)。

2．should意为“按说应该”，表示推测(如例3)，相当于ought to。

3．will 表示主观的意志、意愿(如例4) 及用来叙述目前的习惯(如例5)。

4．would 用来叙述过去的习惯(如例6)。

5．dare有时态的变化(如例7)。

6．need无时态的变化(如例8)。

[名师点津]

1．shall还可表示说话者给对方的命令、指示或允诺

You shall have a new dress for your birthday.

你生日会有一条新的裙子。

2．should还可表示“(义务上的)应该”，在语气上比must (必须)弱。

I should go and visit him this afternoon，but I wonder if I will be free.

今天下午我应该去看望他，但我不知道我是否有空。

3．will/would还可表示请求、建议，主语为第二人称，would在语气上更委婉。

Will/Would you go with me?

你愿意和我一起去吗？

4．would和used to都可表示过去的习惯，但前者表示过去反复的动作，常与every day，often，frequently等连用；后者表示过去的状态或过去的习惯，但现在已不存在。

She doesn't get up so early as she used to.

她不像以前那样起得那么早了。

5．dare作情态动词时，还可用于条件状语从句中。

If you ever dare call me that name again，you'll be sorry.

如果你敢再叫我那个名字，你将会后悔。

[即学即练2]　用情态动词填空

①Shall we order some coffee?

②He dare not go through the woods.

③I don't know why you should think that I did it.

④I still remember my happy childhood when my mother would take me to Disneyland at weekends.

⑤Will you send this letter for me，please?

三、情态动词的特殊用法——表示对过去的推测

[观察例句]

1．She could have gone out with some friends.

2．It must have rained last night，for the road is quite muddy.

3．He might have missed the train.

4．Where can she have put it?

5．It's too late.I think he may have gone to bed.

[归纳用法]

1．must have done sth.表示“(过去)一定做了某事”；语气比较肯定；用于肯定句 (如例2)。

2．may have done sth.表示“也许已经做了某事”(如例5)，may not have done sth.表示也许还没做某事。

3．might have done sth.表示“过去可能/也许做了某事”；语气不确定；用于肯定句(如例3)。might not have done sth.表示过去也许没做某事。

4．could have done sth.表示“过去可能做了某事” (如例1)，could not have done sth.表示过去不可能做了某事。

5．can have done sth.表示“疑虑或惊讶”，用于疑问句 (如例4)，其否定形式为can't/cannot have done sth.。

[即学即练3]　完成句子

①The boy may have known the truth(可能已经知道了事实)，but I am not quite sure.

②Go and ask him about it.He can't/cannot have forgotten (不可能忘了)it.

③Don't worry.Your father may not have been hurt seriously(也许伤得不严重)．

④She's not here.She must have left already(准是走了)．

四、情态动词的特殊用法——表示与过去事实相反

[观察例句]

1．I needn't have taken the umbrella，for the weather is fine.

2．I could have worked out the problem，but I was too nervous.

3．You might have given him more help，though you were busy.

4．Sorry to hear that you had a bad fall.You should have been more careful.

5．I'm sorry.I shouldn't have lost my temper.

[归纳用法]

1．could have done sth.表示过去本可以做某事但实际上没做 (如例2)。

2．needn't have done sth.表示过去本不必做某事但实际上做了(如例1)。

3．should have done sth.表示过去本应该做某事但实际上没做(如例4)，可与ought to have done 换用。

4．shouldn't have done sth.表示过去本不应该做某事但实际上做了 (如例5)。

5．might have done sth.表示过去也许可以做某事但实际上没做(如例3)。

[即学即练4]　完成句子

①We could have faced(本来可以面对) the difficulty together，but you didn't tell me.

②You needn't have worked(本来不必工作)that late last night.The deadline is tomorrow afternoon.

③You should have come(本应该来) to the conference yesterday.

④The pills might have helped him(也许可以对他有帮助) but he didn't take them regularly.

Ⅰ.单句语法填空

1．You needn't worry about my weekend－I always have my plans ready before it comes.

2．For the engine to work，the green lever must be in the “up” position.

3．According to the rule，all the students shall go to school before 8：00 a．m.

4．He should not make this mistake，for he had been reminded several times.

5．You can bring a gift to the hostess，but it needn't be too expensive.

6．Susan's family is very rich and her parents can afford to send her to China for further study.

7．Don't worry，Martin.You shall have a new pair of sport shoes tomorrow.

8．The light in his office is still on.He must be in.

9．I can't thank you too much for all your help to my son while we were away.

10．The children must have got(get)lost in the woods；otherwise，they would have been at the lakeside camp as scheduled.

Ⅱ.短文语法填空

China has become the first country to land a spacecraft on the far side of the moon.The unmanned Chang'e­4 probe(探测器)—the name was inspired by an ancient Chinese moon goddess— 1.touched(touch) down last week in the South Pole­Aitken basin.Landing on the moon's far side is 2.extremely(extreme) challenging.Because the moon's body blocks direct radio communication with a probe，China first had to put a satellite in orbit above the moon in a spot where it 3.could send signals to the spacecraft and to Earth.The far side of the moon is of particular 4.interest(interesting) to scientists because it has a lot of deep craters(环形山)，more so 5.than the familiar near side.Chinese researchers hope to use the instruments onboard Chang'e­4 6.to find(find) and study areas of the South Pole­Aitken basin.“This really excites scientists，”Carle Pieters，a scientist at Brown University，says，“because it 7.means(mean) we have the chance to obtain information about how the moon 8.is constructed(construct)．”Data about the moon's composition，such as how much ice and other treasures it contains，9.could help China decide whether 10.its(it) plans for a future lunar(月球的) base are practical.