(共19张PPT)
Unit 8
Grammar Focus
Let's play a guessing game
It could/might /may be ...
It can't be ...
It must be ...
Guessing Game
Whose hair band is it
It must be a girl’s because many girls have long hair in our class.
=It must belong to a girl because many girls have long hair in our class.
It can’t be a boy’s because many boys don’t have long hair in our class.
=It can’t belong to a boy because many boys don’t have long hair in our class.
It could/might be ...’s because she often wears this kind of hair band.
=It could/might belong to ... because she often wears this kind of hair band.
Whose … is this
It can’t be …’s. Because …
It must be …’s. Because …
It could / might be …’s. Because …
belong to …
belong to …
belong to …
情态动词must, might, could,may, can’t表示推测，后面都接动词原形，都可以表示对现在情况的揣测和推断，但他们含义有所不同。
must 一定，肯定 (100%的可能性)
might, could may有可能，也许 (20%-80%的可能性)
can’t 不可能，不会 (可能性几乎为零)
Whose T-shirt is it
It must be …’s because.... / It must belong to …because...
It can’t be …’s because.../ It can’t belong to...because...
Whose skirt is it
It must be …’s because.... / It must belong to …because...
It can’t be …’s because.../ It can’t belong to...because...
Whose glasses are they
It must be …’s because.... / It must belong to …because...
It can’t be …’s because.../ It can’t belong to...because...
★情态动词+ do/be
此结构表示对将来情况的推测和判断
I think she might travel to Beijing.
He must/might/could /mayarrive before 5 o"clock.
★情态动词+ be doing, 情态动词+ do/be
此结构表示对现在进行的情况或者一般的情况的推测和判断。
At this moment, my father can’t be working in the office.
★情态动词+ have done
此结构表示对过去情况的推测和判断。
The road is wet. It must have rained last night.
情态动词表推测的几种情况
4c Look at this picture of a room. How much can you tell about the person who lives here Is it a boy or a girl What are his / her hobbies Discuss your ideas with a partner.
A: It could be a girl’s room because it’s very tidy.
B: I guess so. But it might be a boy’s room because the clothes look like boys’ clothes.
A:She might/could like music because there is a guitar.
B:He might/could like movies because there is a poster on the wall.
What could he be crying for
He might/could be crying for candies.
He might/could be crying to get his mon’s attention.
He might/could be crying because he doesn’t want to do homework.
He might/could be crying ...
What could he have done before
He might/could have seen something terrible.
He might/could have heard surprising news.
He might/could have done...
4a Choose the best way to complete each
sentence using the words in brackets.
The keys:
might be
must be
could be
can’t be
could be / must be
A: Many people are wearing coats.
B: The weather must be ______________________________.
2. A: Sally has been coughing a lot.
B: She might be _______________________.
3. A: This restaurant is always crowded.
B: The food _______________________.
4. A: Whenever I try to read this book, I feel sleepy.
B: It can’t __________________.
4b Complete these responses.
getting colder / cold outside
having a sore throat / ill
must be delicious
be interesting
Exercise
Fill in the blanks with must, might or can’t.
1
That bright light _________ be a UFO – there’s no such thing!
I’m still waiting for the bus, so I _________ be a bit late for the party.
can’t
could/might
3. That sweater _________ be Carla’s. she’s the only one who wear such colorful clothes.
4. Tony _________ want to go to the concert. He likes music, but I’m not sure if he likes rock music.
5. The person you saw at the supermarket __________ be Susan. I just talked to her on the phone, and she’s at work right now.
must
might
can’t
Look at the chart and write sentences for the things below.
2
Name Likes Dislikes
Jessica take photos run
Todd play the piano eat sweet food
Mike play tennis watch movies
Annie read cook
1. DVD It can’t be Mike’s. He doesn’t like to watch movies.
2. bowl of ice-cream __________________________________
3. camera ___________________________________
4. cookbook
____________________________________
5. tennis ball
____________________________________
6. running shoes
____________________________________
It can’t be Todd’s. He doesn’t eat sweet food.
It must be Jessica’s. She likes taking photos.
It can’t be Annie’s. She doesn’t like to cook.
It must be Mike’s. He likes to play tennis.
It can’t be Jessica’s. She doesn’t like to run.
1.在回答由must引起的问题时, 如果是否定的答复，不能用mustn’t, 而需要用needn’t 或 don’t have to, 因为mustn’t是“禁止”的意思。
2. ought to have done sth., should have done sth. 本应该做某事，而事实上并没有做。否定句表示“不该做某事而做了”。
You ought to (should) have been more careful in this experiment.
ought to 在语气上比should 要强。
注意
