想要學好英語四級怎麼能不知道情態動詞的用法呢?下面就讓小編為大家詳解一下吧。
情態動詞屬於非實意動詞,它雖具有一定的詞義,但這種詞義並不完整,語法上也不能單獨構成謂語,它必須和另一個實
情態動詞屬於非實意動詞,它雖具有一定的詞義,但這種詞義並不完整,語法上也不能單獨構成謂語,它必須和另一個實意動詞一起構成謂語才能表達完整的意思。情態動詞是一類非常活躍的非實意動詞,歸納起來,情態動詞在句子中主要有三種用法:
1.情態動詞的非推測性用法
其用法是用來表示能力、許可、必要、義務、命令、勸告、詢問、需要、應該、敢於等概念或態度,這類情態動詞有:can(could),may(might),shall(should),will(would),must,
oughtto,need,dare等,例如:
Children,you can eat something you like.
Everybody must pay the fare,but you need not do so right away.
How dare you come out without your parents’permission?
I would rather stay at home than go with you.
Ought not parents to give their child more care?
You are not so young;you should not do such silly things any more.
疑問句中的情態動詞和答語中的情態動詞有固定的搭配形式。例如:
-Could I borrow your bike for a while?
-Yes,you can.(-Yes,please.)
-No,you can not.
-May I discuss something on practicing spoken English with you now?
-Yes,you may.(-Yes,of course.)
-No,you mustn’t.
-Need everyone fill in this application form immediately?
-Yes,everyone must.(Yes,everyone do.)
-No,they needn’t.
-Must we hand out emergency rations to these famine refugees this instant?
-Yes,you must.
-No,you they needn’t.
-No,you don’t have to.
2.情態動詞的推測性用法
人們常常會對客觀事物做出自己的判斷,當情態動詞用來表示說話人對事物的推測、判斷時,就具有情態動詞的.推測性用法。可以用作推測的情態動詞有can,could,may,might,must,ought to, should,will和would。它們做出可能性的推測、判斷、預料的程度是不同的,might最弱、最沒有把握,而must最強、把握最大。例如:
It’s nine o’ friend couldn’t come to see me.
This boy must fail in exam from his sad face.
It’s five past e ought to be many students waiting for the door opening.
She should be a clerk in foreign company according to her formal dress.
He may not be fine in these days.
They were ready for a strong earthquake which might occur.
有時,情態動詞用不同的動詞時態來推測表達對不同時間的事物的推測,例如:
My friend may be still sleeping at home now.(對現在說話時正在發生的事物的推測)
Can we be working at the same company next year?(對將來的推測)
His clothes is must have forgotten to bring the umbrella.(對已經完成的情況的推測)
3.情態動詞用於虛擬語氣
A:提出一個假設的條件,純粹的展望或提出命令、要求。有部分情態動詞的過去時態常用於這種用法。
例如:Wish I might be better soon.
Should my friend come,ask him to wait in the reading-room.
May you be healthy forever.
If you dared to say such words to me,I would give up making friends with you.
B:比較委婉地陳述看法,提出要求和建議,謂語動詞通常是情態動詞的過去時態。例如:
It would not be useful to adopt such suggestion.
Could you leave the message with me?
C:情態動詞加動詞的完成時態用來表示對過去情形的虛擬,這種設想或看法同過去的事實是相反 的,表示"本應該做",而實際上沒做。例如:
We ought to have been here early.
This is something you shouldn’t have done.
Need you have nosed about in her affair?It was none of your business.