be able to 与can使用方法不同(1) be able to 强调通过努力而获得的能力，而can则强调自己已具备的能力。如：She can sing the song in English. 她可以用英语唱这首歌。He will be able to sing this song in English in a few minutes, too. 几小时之后，他也可以用英语唱这首歌。(2) be able to 强调一种结果，而can只强调一种可能。如：Luckily, he was able to escape from the big fire in the end. 幸运的是，他终于逃出了大火。If he got here a few hours earlier, I could save him. 如果他早几小时来，我还能救他。(3) be able to 可以有各种时态；而can只有一般目前和一般过去两种时态。如：I could help you last night, but you didn’t come. 昨天晚上我能助你，而你又没来。Can you see it there? 你能看见它在那儿吗？He is / was / will be able to help you. 他能助你的忙(from www.hxen.net)。(4) can可用于表示可能性，推断，允许等状况，而be able to一般不如此用。■点击→英语疑难问题·综合解答■
be able to 与can用法区别