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1、十三、can(could)和be able to的区别辨析一、can(could)只有两种形态，而be able to 可以根据“人称和时态”的变化有各种不同的形态： am(is、are)able towas (were)able towill be able tohas(have)been able tohad been able to二、两者基本含义相似：“能、能够”，但细分起来can(could)有三种基本含义：1. 能力； 2. 请求许可； 3. 可能性。而be able to 只能表示一种“能力”。 (一)、can(could)表示“有能力、能够”。这时可以和be able to 互
2、换。l He will come if he can.l He will come if he is able to.l I can see you tomorrow.l I will be able to see you tomorrow.l I couldnt understand him.l I wasnt able to understand him.l He said he could see me next week. l He said he would be able to see me next week. (二)、can(could)表示“请求别人的许可”, 这时不可以和b
3、e able to 换用。l Mom, can I watch some TV?l Could you please turn it a little down? (三)、can(could)表示“可能性”，也不可以用be able to 替代。l My mom cant be at home at this time.l It couldnt be an animal. It could (might) be some mischievous kid playing tricks on you. 三、在表示“某个动作被成功完成、某个计划被成功实施”时，只能用was able to (be able to 的过去式)，不可以用could。l He was able to go to London yesterday and he enjoyed himself very much.l He didnt agree with me at first but I was able to persuade him.l Lots of Jews were able to flee Europe before the World War began.