文档介绍：Modal Verbs
Maggie. L
Ⅰ.特点和基本用法
情态动词有四类: ①只做情态动词:must, can (could), may (might), ought to ②可做情态动词又可做实义动词:need, dare ③可做情态动词又可做助动词:shall (should), will (would) ④具有情态动词特征:have (had) to, used to; had better
Modal Words
特点
无人称和数的变化, 后跟动词原形,否定式是在其后加“not”。
有现在式和过去式。过去式更加客气、委婉。
时态性不强, 可用于过去,现在或将来。
情态动词属非及物动词,没有被动语态。
Modal Words
1. can; could
表示能力和客观可能性,还可表示请求和允许
can/could=
is /was/will be/
has been able to
1).No one can do it.=No one is able to do it.
Note:“某事已成功”,
应用was/were able to,而不能用“could”。
2). 表示惊异、怀疑、不相信的态度。
(主要用在否定句、疑问句或惊叹句中)
Can this be true?
3). cannot be too +adj.
cannot be + adj.+ enough
表示"无论怎样……也不过分","越……越好"
Gas is very dangerous.
You cannot be too careful with it.
2. may ; might
(1) 表示请求、允许
May I use your pen?
用May I ... 比较正式,口气上比较客气。
2). 用于祈使句中表示祝愿。
May you eed!
(3) 表示推测:may+动词原形------对现在情况推测,意为“也许”。
He may be very busy now.
may (might) + have + 过去分词
表示对过去发生的行为的推测
He may not have finished the work.
表猜测时不用于疑问句
4)表示让步和目的
Talk louder, so (that) all may hear.
You are so careless that you may break the vast.
Here lies those who fought and died, so that we might live.
3. must
(1) 表示必须、必要
You must wait here.
(2) must 表示的是说话人的主观看法,have to往往强调客观需要
The play is not interesting. I really ________go now.
I _________ work when I was your age.
must
had to