商丘一高2015—2016学年度英语语法复习
学案
情 态 动词
i 情态动词的特征：
1.本身有词义。
2.不能独立作谓语。
3. 后接动词原形一起构成谓语。
4. 不随人称和数的变化。
ii 情态动词各自的基本意义及用法：
一.can和could
情态动词用法例句
can
/could
表示能力1．“i don’t think mike can type.”
“yes, he can.”
2．i can speak fluent english now , but i couldn’t last year.
在肯定句中，表示客观可能性，并不涉及具体某事会发生，常用来说明人或事物的特征。要表达具体某事实际发生的可能性时，不用can，需用could，may，might。1．as a human being, anyone can make a mistake.
2．i’m confident that a solution can be found.
3．he can be very forgetful sometimes.
4．i may stay at home this weekend.（实际可能性）
5．peter might come to join us.(实际可能性)
6．it will be sunny in the daytime ,but it could rain tonight.(实际可能性)
表示请求和允许。表示请求，口语中常用could代替can，使语气更委婉。1．can we turn the air conditioner on?
2．any police officer can insist on seeing a driver’s license.
3．in soccer, you can’t touch the ball with your hands.
4．could you have her call me back when she gets home, please?
5．i wonder if i could just ask you to sign this.
表示对现在的动作或状态进行主观的猜测，主要用在否定句和疑问句中。1．it can’t be easy caring for a man and a child who are not your own.
2．can the man over there be our head master?
表示惊异、怀疑、不相信等态度，主要用在否定句、疑问句和感叹句中。1．can this be an excuse for not giving them help?
2．this can’t be true.
3．how can you be so crazy?
