过去该做而没有做
You should have come to school if you were really serious about your study.
5.should not /ought not to have done
做了不该做的事（过去）
We oughtn’t to have given him so much money.
You mustn’t take photos here!
回ห้องสมุดไป่ตู้must/need的一般疑问句时，肯定回答用must;否定回答用needn’t/don’t have to
Must I come back home early? Yes, you must.
Need I come back late? No, you needn’t/don’t have to.
Where can I have put my keys?
2.may/might
允许
May I smoke here?
表示祝愿
May you a happy life!
针对不同时间表示推测（只能用于否定句和问句）
may do
He may come, but he is not sure.
may be doing
7.would
表示意愿
He said he would give me a gift.
表示请求
Would you please clean up the messy room?
习惯性动作，指过去
We would sit around grandpa, listening to his story.
8.need/dare半情态动词
Why should you be so late today?
6.will
表示意愿
Tom is ill at home. I will see after school.
表示请求
Will you please open the door for me?
习惯性动作， 指现在
Accident will happen.
The machine needs repairing. = The machine needs to be repaired.
9.ought to
应该
否定形式：oughtn’t/ought not to
You ought to make an apology to him.
He oughtn’t attend the meeting.
3.may/mightnothave done
表示对已经发生的事进行推测，可能性不大
I can’t find purse anywhere. You may have dropped it when you were shopping in the market.
4.should/ought to have done
针对不同时间表示推测（只能用于肯定句）
must do
Tom must study hard, for he always gets the first placeeverytime.
must be doing
It’s so noisy upstairs. They must be quarreling again.
must have done
It must have been around 9:00, becauseit wastotally dark.
4.shall
一三人称的问句表示请求
Shall he wait here?
What shall we do next?
二三人称的陈述句表示允诺，警告，命令，威胁…
Jeff is clever, but sometimes he is very dull.
针对不同时间表示推测（只能用于否定句和问句）
can’t do
He can’t be at home right now, for I saw him go out just now.
can’t be doing
He can’t be studying in the classroom, for I saw him go to the football field with a football.
can’t have done
He can’t have finished homework so soon, for he didn’t come to school yesterday.
6.could have done
过去本来可以做某事，但没有做
He could have visited the Great Wall but it suddenly began to rain yesterday.
7.couldn’thave done
过去不能做而做了的事
He couldn’t have known the decision, but someone told him.
Jim may be reading in the library.
may have done
He may have left the bag in the library.
3.must
肯定形式表示必须，应该;否定形式表示绝对禁止，语气强烈
You must have a passport if you want to go abroad.
8.needn’t have done
过去不必做的事却做了
You needn’t have finished the homework because you were ill.
1.can/could
能力
He can sing songs in French.
He could swim at the age of 3.
表示请求
Can you help me carry the box into the room?
Could you help me, please?
可能性， 表示有时会
2.cannot have done
对过去的否定推测（只能用于否定句）译为“过去肯定没有…”
Hecan’t have gone far, for his coat is still here.
can have done
还可用于问句表示对过去的推测
Where can he have put the bag?
作情态动词时常用于否定和问句中；作实意动词时常用于肯定句
Need I tell him all? You needn’t tell us.
He dares to answer questions loudly in front of us.
need doing是主动表示被动=need to be done
You shall get an answer tomorrow.
5.should
劝告，建议
You should see your parents regularly.
根据客观事实作出的的判断，可能性较大
It’s 7:20. He should come.
why/how+should 表示说话人对某事不能理解，感到意外，译为“竟会”
10.have to
不得不
I can’t see things clearly, I have to wear glasses.
情态动词+have done
1.must have done
对过去的肯定推测（只能用于肯定句）译为“过去肯定…”
She must have earned much money, for he bought an expensive car last week.