模式动词在英语中的差异.doc

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. 特别说明： （1） could用来表示请求时，语气委婉，主要用于疑问句，不能用于肯定句，答语应用can（即：could不能用于现 在时态的简略答语中）。如： ——Could I use your dictionary? ——Yes, you can.(否定回答可用：No, I’m afraid not.) (2) can和be able to辨析 can(could)和be able to都可以表示能力，意思上没有区别。但can只有现在式和过去式，而be able to则有更多的形式。如： I’ve always wanted to able to speak fluent English. Those bags look really heavy, are you sure you’ll be able to carry them on your own? 但是，表示在过去某时的某一场合经过一番努力，终于做成了某事，通常不用could，而用was/were able to来表示。这时，was/were able to相当于managed to do或succeed in doing。如： After the accident it was a long time before she was able to walk again. The fire was very big, but most people were able to escape from the building. 二．may和 might 情态动词 用法 例句 may/might 表示允许、许可。否定回答一般用must not/mustn’t,表示“禁止、阻止”之意，但也可以用had better not (最好别)或may not（不可以），语气较为委婉。 1． May I come in and wait? 2． ——May I smoke here? ——No, you mustn’t(或No, you’d better