时间:2019-02-01 作者:英语课 分类:英文语法词汇


英语课
特征
1)情态动词(modal verb)本身有词义,表示说话人的语气或情态,但词义不完全,不能单独用作谓语动词,一般只能和动词原形一起构成谓语动词。
2)情态动词所表示的情态有:命令、允诺、请求、拒绝、愿望、愿意、义务、必要、可能、能力、敢于、需要等。
3)情态动词(ought除外)和助动词shall,will,should,would一样,后面的动词不定式一般皆不带。
形式变化
1)没有人称和数的变化,第三人称单数的现在时也无变化。如:
I can We can
You can You can
He
They can
She can
It 
2)有些情态动词有过去式,有少数过去式和它的原形相同。
a)有过去式的情态动词有:
may —— would
can ―― could
may―― night
shall —— should
have to —— had to
b)过去式不变的情态动词有:
must — must (或had to)
ought to — ought to
need———need
dare — dare(亦可用dared)
3)大多数情态动词后面可用动词的进行式、完成式和被动形式,如:can(may,must)be doing,can(may,must) have done,can(may,must)be done等。
否定式
情态动词和助动词一样,后面可直接跟否定词not。现将情态动词的否定式及其否定式的简略式(简略式用于口语中)列举如下:
shall not——shan't [FB:nt]
will not———won't [wEunt]
can not—can't [kB:nt]
must not—mustn't [5mQsnt]
should not—— shouldn't
would not—— wouldn't
could not—— couldn't
dare not— daren't [dZEnt]
need not—— needn't

在疑问句中的用法
情态动词在疑问句中的用法和助动词相同。如:
May I ask you a question? 我可以问你一个问题吗?
Can you let me use your dictionary for a minute? 你能把字典借我用一会儿吗?
Would you like to visit the heavy machinery plant? 你想参观重型机器厂吗?
注意have to在疑问句中的位置。如:
Do you have to go out today? 你今天一定得出去吗?
Does he have to finish the work tomorrow? 他明天非做完这项工作不可吗?


学英语单词
active infrared tracking system
adors
affronty
Alice B. Toklas
alisphaera unicornis
aquatic ferns
ballistic control
banci rarratores
beam monitor
bending die
bias uncertainty
bitter betch
Breakfast Vlei
Bungis
Calotropis gigantea
Castelflorite
centre zone profile
cerebroprotective
cirriferous
cochlear
collion
cooling tube
couplet on pillar
cross-over pipe
current passbook
curtaxe
dishonoured notes account
district public security bureau
ductulus deferens
enrobed
equivalent samples
expansion process
faraways
frontolyzing
geo-stationary
geological model
ginger rhizome
graphite water
hamilton-river
heavy-atom derivative
heroicomic
Hoogwoud
ICDH
identifyees
imperial scale
insufficient feed
inverse compensation
Irosul
jackstraw
janka hardness
jessica lucy mitfords
la camargue (camargue)
laser transition frequency
LBDs
levulosazone
lipotoxic
Mahonia hancockiana
marginal profits
net income to sales ratio
origin hypothesis of earth
originated tonnage
outgoing trunk jack
Panhellenic Socialist Movement
paniclike
paradasynus formosanus
phaeoisaria clematidis
phylosophies
plasma immersed modification
position length
poz
precita
put one's money on the wrong horse
Ramus mylohyoideus
range scale
reflexivizable
retrieval usage mode
ribbon left guide
rotten wood
Salem limestone
sarti
satellite receiver
school-college
schopenhauers
sedlmayr
side-curtains
skolnicks
software debugging aids
spath
Squaw Valley
squawk box
st. nicholass
supergrid substation
swaddling clothes
thought broadcasting
trade fixtures
transistor seconds
trent
Typhoid-Paratyphoid
westfjords
wous
wudu
yumm-yumm