专题七 情态动词和虚拟语气常考点
近两年考查情态动词和虚拟语气的频率呈上升趋势。从整体上把握情态动词的语法特征和语义特征，能够准确理解不同情态动词的细微差异，认真区别具有相同功能、意思相近的情态动词的用法，在真实的交际情景中印证和领悟情态动词的用法和特征。
1 情态动词所表示的多种含义
1. can和could的用法 ①表示能力。如： I can run fast.
②表示客观可能性。如：
An experienced driver can have an accident at times. ③表示请求和允许。用could 语气更委婉。如： —Can/Could I go now? —Yes，you can.
④表示猜测、惊异、怀疑、不相信的态度(主要用于否定句、疑问句或惊叹句中)。如： Can this be true?
How can you be so careless! This cannot be done by him. 2. may和might的用法 ①表示许可。如：
You may drive the car.
—May/Might I use your pen? —No，you mustn't.
②用于祈使句中表示祝愿。如： May you succeed!
③表示推测、可能(疑问句不能用于此意)。表推测的might并不是指过去时间，而表示比may把握性略小些。如：
He may be very busy now.
④用于表示目的或让步状语从句中。如：
No matter what difficulties you may come across，you shouldn't give up. 3. will和would的用法
①用于各种人称，表示“意志”“意愿”“决心”等。如：
I told her to stop crying，but she just would not listen.
②用于第二人称的疑问句，表示说话人向对方提出请求。用would比用will语气更客气。如：
Will/Would you please keep the door open? ③表示真理或习惯，意为“惯于，总是”。 如：
She will listen to music alone in her room for hours. He would get up early when he lived in the country. 4. should的用法
①表示现在或将来的责任或义务，意为“应该，应当”，这时它可以和 ought to，be supposed to 互换使用。如：
You should(＝are supposed to ) complete your test in time.
②表示有较大可能实现的猜测、推论，通常意为“可能；总该……吧”，相当于 be expected to。如：
They should be home by now，I think.
③用于第一人称时可以表示说话人的一种谦逊、客气、委婉的语气。如： I should think it would be better to try it again.
④用在条件状语从句中，表示语气较强的假设，意为“万一”，这时也可将should置于从句之首，即将should放在主语前面，而省略从属连词if，主句谓语却不一定用虚拟语气。如：
Should I (＝If I should) be free tomorrow I will come.
⑤用来表示意外、惊喜或者在说话人看来是不可思议的。尤其在以 why，who，how 等开头的修辞疑问句或某些感叹句中常常意为“竟会，居然”。如：
A gentleman like him should be rude to a lady! ⑥用于虚拟语气句中(略)。 5. ought to的用法
表示应该、推测，相当于should。 如： You ought to take care of him. 6. shall的用法
①用于第二、三人称，表示说话人的意愿，有“命令”“警告，威胁，强制”“法令条文规则”和“允诺”等意思。 如：
You shall have the book when I finish reading.(表允诺)
②在疑问句中，shall用于征求对方的意见或请求指示，常用于第一、第三人称。如： Shall we go out for a walk? Where shall he wait for us? 7. must的用法
①表示义务、意图或建议，意为“必须，应该，禁止(用于否定句中)”。 如： You must go and see that film—you'd really enjoy it. ②表示推测，意为“必定，一定”。
[注]must表示推测时的否定式是can't或couldn't(不可能)。 ③表示主张，意为“硬要，一定要”。如：
If you must go，at least wait till the rain stops. ④表示与说话人愿望相反，意为“偏要”。如：
The machine must break down at this busy hour. 8. need和dare的用法
①need 作“必要”讲时，既可作情态动词，也可作实义动词。作实义动词时后面的动词不定式要带to，其变化与一般动词相同。作情态动词时，仅用于否定句或疑问句中。
②dare作为情态动词时，仅用在疑问句、否定句和条件从句中。dare若作实义动词，后面可接带to的不定式，此时to也可以省略。dare与need的用法相似。如：
He dares to go there alone. He needs to go there alone.
She doesn't dare (to) ask her father. She doesn't need to ask her father.
He daren't speak English before such a crowd，dare he? 9. used to的用法
used to表示过去的习惯动作或状态，现在已不存在，在间接引语中，其形式可不变。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 否定句 否定疑问句 ·Did you use to go to the same school as your brother? ·Used you to go to the same school as your brother？ ·I usedn't to go there. ·I didn't use to go there. ·Usen't you to be interested in the theatre? ·Didn't you use to be interested in the theatre？ 其反意疑问句或简略回答中，也有两种形式： She used to be very fat，didn't she？(正式)/use(d)n't she? (口语) —Used you to get up early in the morning? —Yes，I did(正式)．/Yes，I used to.(口语) 10. would rather (not) do 宁愿(不)做 11. had better (not) do 最好(不)做
①I ________ often go fishing when I lived in the countryside. A. should B. would C. could D. might
②I've decided to take the job and I ________ change my mind. A. mustn't B. can't C. won't D. may not
③“Whatever you want，you ________ have it on condition that you get the best result，” said the boss.
A. would B. ought to C. shall D. could
④—Why ________ you stay in the countryside，where it's not convenient to go shopping?
—But I've found it rather valuable for my health. A. can B. must C. may D. shall
⑤—I promise her daughter ________ get a nice present on her birthday. —Will it be a big surprise to her? A. should B. must C. would D. shall
⑥She just couldn't believe that her husband，to whom she had been loyal for so many years，________ desert her after he became rich.
A. might B. should C. shall D. must
⑦—A Mr. Smith is waiting outside for the appointment with you. ________ he come in?
—Yes，please let him in.
【最高考】2016届高考英语语法精讲精练-专题七-情态动词和虚拟语气常考点
