情态动词有can, may, must,
ought(to), will ,shall, dare, need
Modal verbs can be used for-
possibility: can / could, may / might
certainty: must, will, should
ability: can / could, be able to
permission: can / could, may / might
requests: can / could, will / would
suggestions: could / may /might,
necessity: must, have to, have got to,
advice: ought to, had better
Ⅱ.Some Special Usages：
1.只用be able to的情况：
was/ were able to,不能用could。
2.成语:may/might as well,后面接不带
e.g. If that is the case, we may as well
1) may (might) have + done sth., can
(could) have + done sth. 表示过去,推
e.g. Philip may (might) have been hurt
seriously in the car accident.
Philip can (could) have been hurt
seriously in the car accident.
2) must have+done sth., 表示对过去
e.g. --- Linda has gone to work, but
her bicycle is still here.
--- She must have gone by bus.
3) ought to have done sth.\should have
e.g. You ought to (should) have been more
careful in this experiment.
He ought not to have thrown the old
注: ought to 在语气上比should 要强。
4) needn’t have done sth. 本没必要做某事
e.g. I dressed very warmly for the trip, but I
needn’t have done so. The weather was
5) would like to have done sth. 本打算做某事
e.g. I would like to have read the article, but I
was very busy then.
have done 用来表示与过去事实
•e.g., If I had been free that day, I
would have gone with you.
4. had better表示“最好”
had better 相当于一个助动词,它只
形。had better (not) do sth.
e.g. It is pretty cold. You’d better put on my
She’d better not play with the dog.
had better have done sth.表示与事
e.g. You had better have come earlier.
5. would rather表示“宁愿”
would rather (not) do\would rather(that)sb
did\had done sth
would sooner\ had rather\ had sooner
e.g. If I have a choice, I had sooner not
continue my studies at this school.
1. A left-luggage office is a place
where bags ____be left for a short
time, especially at a railway station.
A. should B. can
C. must D. will
2. My English-Chinese dictionary has
disappeared. Who C have taken it?
A. should B. must
C. could D. would
3. — Is John coming by train?
— He should, but he ____ not.
He likes driving his car.
A. must B. can
C. need D. may
4. — I heard they went skiing in the
mountains last winter.
— It ____ true because there was
little snow there.
A. may not be B. won’t be
C. couldn’t be D. mustn’t be
5. — I hear you’ve got a set of valuable
Australian coins. ___ I have a look?
A. Do B. May C. Shall D. Should
6. Oh, I’m not feeling well in the
stomach, I ___ so much fried
chicken just now.
A. shouldn’t eat
B. mustn’t have eaten
C. shouldn’t have eaten
D. mustn’t eat
7. — Write to me when you get home.
A. I must B. I should
C. I will D. I can
8. Sorry, I’m late. I ___ have turned off
the alarm clock and gone back to
A. might B. should
C. can D. will
9. There was a lot of fun at
yesterday’s party. You ___ come,
but why didn’t you?
A. must have B. should
C. need have D. ought to have
10. The fire spread through the hotel
very quickly but everyone ___
A. had to B. would
C. was able to D. could
11.When he was there, he ___ go to
that coffee shop at the corner after
A. would B. should
C. had better D. might
12. Sir, you ___ be sitting in this
waiting room. It is for woman and
A. oughtn’t to B. can’t
C. won’t D. needn’t
13. I wonder how he ___ that to the
A. dare to say B. dare saying
C. not dare say D. dared say
14. I told Sally how to get here, but
perhaps I ____ for her.
A. had to write it out
B. must have written it out
C. should have written it out
D. ought to write it out
15.—When can I come for the photes? I need
them tomorrow afternoom.
--They ___ be ready by by 12:00.
A.can B.should C.might
Review and practice Modal verbs.