情 态 动 词
1.表示能力时，只能用can (现在) could do (过去能做) 北京地图最新版2023was/were able to do ：
（1） 过去能做
( 2 ) 过去设法成功完成某一具体动作 =manage to do
=succeed in doing
Eg. 1.A blind man can not judge colors.
2.He could/was able to swim like a fish when he was young.
3.Though he was tired , he was able to swim across the river.
4.Because he was tired, he couldn’t /wasn’t able to swim across the river.(在否定结构中无区别)
2.表推测时：may/might( 语气最不肯定，多用于肯，否定句) 可能 can （语气肯定，一般不用于肯定句）可能
could (较can不确定，也可用于肯定句) 可能
must (语气最肯定，只用肯定句)一定
should(表可能性，推论，推测，期待等)按理该；估计
ought to (表可能性，揣测，猜测，期望等)照说应该，理应
may/might have +ed (语气不肯定) 过去可能……
can’t/couldn’t have +ed (语气肯定)过去不可能……
must have +ed (语气肯定) 过去一定
should have +ed 过去按理应该
ought to have +ed 过去按理
Eg. 1.A: Look, someone is coming. Who can it be?
B: It may be the headmaster.
A:It can not be him.He has gone to Shanghai.
B: It must be Mr Zhang. He looks like the headmaster.
2.I don’t know his age. He could be thirty or thirty-five.
3. The report is written after careful investigation, so it
should be reliable.
4.---I didn’t see Mary at the meeting yesterday.
---She might have been ill, I guess.
5.The street are all dry. It couldn’t have rained成都旅游攻略自由行攻略五天 during the night.
3. 表责备时：
may/might have +ed（语气委婉）过去本可能…
can/could have +ed (语气委婉) 过去本能……
should have +ed (语气强烈) 过去本应该……，而未……
ought to have +ed (语气强烈) 过去本应该……，而未……
needn’t have +ed 过去本不必沈阳棋盘山动物园门票多少钱…，却做了…
Eg. 1.He might have given you more help, even though he was very busy.
2.---Did you listen to the speech?
----No, we could have attended it.But we had a lot of traffic on our way.
3.The plant is dead. Maybe I should have given more water.
4.Your brother’s failed in English again. You ought to have given him more help.
5. ---Mr Smith didn’t come last night, did he?
---- No. We needn’t have waited for him. A whole night was wasted.
4.表未曾实现：
was/were to have +ed 过去本打算/本想……
should like /love to have +ed 过去 本想…… 而没……
=would like/love to have +ed
=should have liked /loved to do
=would have liked/loved to do
had better have +ed 当初最好……
would rather have +ed 当初真该……
Eg. 1. He was to have come here yesterday, but he had an important meeting to attend.
2. We would like to have gone to see the film, but we had no time.
3. I would love to have gone to the cinema to see the film that day, but the tickets were all sold out.
4. I should have liked to stay another week, but I had to go back to work.
5.We had better have bought (当时真该买) the book.
6.She would rather have stayed (当初真该呆) at home than go to see the dull film.
5. 委婉的请求 肯定的答语
could can
might may
would will
Eg. 1. ---Could you lend me your book?
---Certainly, I can.
2. ---Might I ask you a question?
---Surely, you may.
温州自驾游去哪里好玩3. ---Would you do me a favor?
---Of course, I will.
4. ---Would you like to do it for me?
---Yes, I’d like to. ( 特殊)
7. Shall : 可 用于一、三人称表示征询对方意见或请求指示 Eg. Shall he wait for you at the gate?
Shall we begin our lesson?
Shall 用于第二、第三人称， 表示说话人对对方的命令、警告、允诺或威胁。
He shall be punished. ( 威胁)
You shall have the book when I finish reading.（允诺）
You shall fail if you don’t work harder. (警告)
8.dare :作情态动词时，主要用于疑问句、否定句和条件从句中，一般不用于肯定句。Eg. How dare you say I’m unfair!
He daren’t speak English before such a crowd, dare he?
dare杜莎夫人蜡像馆香港作实义动词时，在肯定句中，其后通常接带to的不定式；在否定和疑问句中，其后可
接带to或不带to的不定式。
Eg.I dare to swim across this river.
He does not dare (to) answer.
9. Need 表示“需要”或“杭州都有哪些景点好玩必须”，作情态动词时，仅用于否定句或疑问句中。在肯定句中一般用 must,have to, ought to 或should 代替。
Eg.You needn’t come so early.
--- Need I finish the work today?
---Yes, you must.
10.used to 表示过去的习惯动作或状态（现在已不复存在），在间接引语中，其形式可不变。
Eg.He told us he used to play football when he was young.
在疑问句、否定句、否定疑问句或强调句中，可有两种形式：疑问句
Did you use to go to the same school as your brother?
Used you to go to the same school as your brother?
否定句：I usedn’t to go there.
I didn’t use to go there.
Usedn’t 亦可拼作usen’t
否定疑问句：Usen’t you to be interested in the theatre?
