情态动词课件

情态动词themodalverb情态动词themodalverb1一、情态动词的特点:

1.没有人称和数的变化。

2.

有些情态动词有过去式的变化:

e.g.

will

→

would

,

can

→

could

,

may→

might

,

dare

→

dared

一、情态动词的特点:

2本身有一定的词义，但不能独立做谓语，它和实义动词一起构成合成谓语。常用情态动词can/could;may/mightmustshould/oughttoshallwilldareneed补充短语：cannever/can’t…….too无论怎样也不过分。越。。。。。越好youcan’tbetoocarefulwhilecrosstheroad.情态动词本身有一定的词义，但不能独立做谓语，它和实义动词一起构成31Can表示与生俱来的一种能力beableto强调通过后天学习和努力获得的能力或在某个客观的场合和背景下能做到的。Hecanswim,andhewillbeabletoswimashorewhentheboatsinks.2表示一种许可其中could比can更委婉、更礼貌。CouldItakethisseat,please?canIuseyourpen?Yes,youcan.1Can表示与生俱来的一种能力beabl43

表示可能性

hecan’thavegonetoshanghai,becauseIsawhimjustnow.Couldhavedone本该做而未做（与过去事实相反的假设）hecouldhavegonetherebybus.4表不肯定

canthisbetrue?Itcan’tbetrue.Doyouthinkhecouldhaverememberedthedetailsunderthosecircumstances?can/could的用法3表示可能性can/could的用法51、用于正式场合表示许可MayIuseyourdictionary,professorsmith?yes,youmay.2、用于肯定句，疑问句，否定句中表示可能性You’dbettertakeanumbrellawithyou;itmayrain.ifhehadfollowmyadvice,hemighthavepassedthedrivingtest.May/might的用法1、用于正式场合表示许可May/might的用法63、用于感叹句中表示愿望

mayyouhaveagoodluck.4、用于目的状语从句中表示“目的”Westartedearlyinthemorningsothatwemightarrivethereintimeforthemeeting.5、表示让步Anystateshouldprovideitspeoplewiththerighttoexistnomatterwhatpoliticalsystemitmayadopt.3、用于感叹句中表示愿望71、表示即刻或将来的责任或义务Youmustcleantheclassroomafterschool.对must的提问回答要用needn’t注意：must指自己的主观的责任或义务，haveto指外界施加的责任或义务Imuststudyharder.Ihavetostayathomelookingaftermymotherbecausesheisill.Must的用法：1、表示即刻或将来的责任或义务Must的用法：82、must用于否定句中表禁止

youmustn’tplayfootballinthestreet.3、用于肯定句中表示“确定或可能”

youmustbeastudent.Imustlookfunnyinthishat.4、表示很有把握的推断:

一定,

准是。have

to

2、must用于否定句中表禁止91).

表示必须要做的事:

必须

3)

-Must

I

get

to

the

station

before

three

o'clock?

Yes,

you

must.

(

No,

you

needn't.

)

4)

I'm

afraid

you

will

have

to

wait

a

while.

6)

Mary

____

be

in

Paris,

I

saw

her

in

town

only

a

few

minutes

ago.

A.

mustn't

B.

shouldn't

C.

can't

D.

may

not

3.

must

C1).

表示必须要做的事:

必须

3.

must101、should加动词原形表示责任、义务、建议；weshoulddoourworkwell.2、虚拟语气中should可以省略。Should用在虚拟语气中表示“惊讶、失望、目的”It’sstrangethatyoushouldsaythattoyourmother.Should的用法：1、should加动词原形表示责任、义务、建议；Shoul113、shouldhavedone过去该做而没有做的事，含有委婉的责备eg:youshouldhavetoldmethatnewsearlier.Should+havedone针对过去某事的推测hestartedsoearly,soheshouldhavearrivedbynow3、shouldhavedone过去该做而没有做的事，121、表道德义务或建议yououghttogothereatonce.2、oughttohavedone对过去某事的推测或责备

yououghttohavestudiedharder.注意：oughtto的语气比should强oughtto的用法：1、表道德义务或建议oughtto的用法：131)

You

to

smoke

too

much.

2)

She

____

for

what

she

has

done.

A.

ought

to

praise

B.

ought

be

praised

C.

ought

to

have

praised

D.

ought

to

be

praisedoughtn't1)

You

to

smoke

t141)

Don't

smoke

in

the

meeting

room,

___

you?

A.

do

youB.

will

you

C.

can

you

D.

could

you

2)It's

my

birthday

tomorrow.

Don't

forget

to

come

to

my

party.

-

_____

.

A.

I

don't

B.

I

won't

C.

I

can't

D.

I

haven't1)

Don't

smoke

in

the

meeting

15YouhavemydictionaryassoonasMaryreturnitto.A.willB.shallC.wouldD.shouldHecanswim,andhesurvivewhentheboatsinks.A.canB.isabletoC.mayD.couldBBYouhavemydiction16

Icleantheclassroom?No,you

Mymotherisillinbed,andIstayathomeandlookafterher.HetakeanapafterlunchandhaveawalkaftersupperIuseyourpen?Yes,ofcourse.Maryisverytimid.Shegooutatnight.Thegroundiswet.Ithaverainedlastnight.Sinceyouarehiselderbrother,youtakecaregoodofhim.mustneedn'thavetowould/willcan/maymustshould/mustIcleantheclassr17

1.

be

able

to

表示经过努力后,

能够做到;

2.can

1).

表示体力或脑力方面的能力;

2).

表示允许、可能性。

could

是can的过去式,

表示过去有能力及过去存在的可能性

;

用于疑问句表示委婉地提出问题。can

,

be

able

to

can

,

be

able

to18

1)

The

fire

spread

through

the

hotel

very

quickly

but

everyone

____

get

out.

A.

had

to

B.

would

C.

could

D.

was

able

t