内容正文:
语法专项知识清单:情态动词
一、情态动词:有一定词义,不能单独做谓语,+动词原形
用法
否定
句型
can
1. 表能力,“能、会”=be able to
2. 表请求、允许“能、可以”
3. 表可能性,推测“可能”
can’t
不会
不可以,不能
不可能(推测)
He can speak English. _________
He could speak a little Russian when he was living in Russia.______________
He can't be a doctor. ______________
Anybody can make mistakes. ______________
Could / Can you help me ? ______________
could
1. can的过去式
2. 比can更委婉客气,不是过去式(一般用于一般疑问句)
couldn’t
may
1. 表请求、允许“能、可以”
2. 表可能性,推测“可能、也许”
3.表祝愿 (不用might)
may not
不能,不可以;
可能不(推测)
-May/Might I watch TV after supper?
---NO,you may not.(不可以)//No,you mustn’t(不可以)//No,you’d better not.(最好不要)
He may / might be a doctor. ______________
He may not be a doctor.______________
May you succeed !______________
might
1. may的过去式
2. 表请求、允许“能、可以”,比may委婉,不是过去式
3.表可能性,推测“可能,也许”,might可能性比may小
might not
will
1. 表示意愿、趋势,“会,将”
2. 表请求,用于第二人称疑问句中
3. 表示习惯或特性
won’t
不会,不将
Will/ Would you go with me ?
I will help you. ___________________
Fish will die out of water.___________
They said they would help us.
During the vacation,he would visit me every other day.
would
1. will的过去式
2.表请求,用于第二人称疑问句中时would 比will 更委婉,不是过去式
wouldn’t
must
1. 表“必须”,主观要求
2. 表可能性,推测“一定”,只用于肯定句(否定句表不可能用can’t)
无
mustn’t不许、禁止 ★
I _______ keep my word.
It rained heavily,so the children _______stay at home.
He _______leave now,for it’s dark.
-Must I go now?
-Yes,you must.//No, you_________/____________.
You don’t have to park your car here.______________
You mustn’t park your car here.______________
--Who is there at the door?
--It _____ be your brother.It must be my brother.
have to
1.表“必须,不得不”,客观需要,有人称、时态和数的变化
don’t have to不必
shall
1. 表征求意见或请求允许,在疑问句中,用于一、三人称
2. 在陈述句中,用于二、三人称,表命令、警告、允诺等
shall not /shan’t
________we start now?
You shall fail if you don't work hard.(警告)
We ________/___________ learn how to use computers. 我们应该学习如何使用电脑。
You ________ /_____________ feel unhappy.你不应该感到不愉快。
should
表劝告,建议“应该、应当”
should not
ought to