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!