3. I never feel ____________ because I have a lot of friends here.

2. When his wife and two little children left him, he was very

　 _____________.

1. Don’t leave the baby ____________ at home.

5. 当表示现在或过去的“能力”时，两者可通用。

　eg, No one was able to/could answer the question.

课堂小考场1

I. 用 lonely 或 alone填空：

4. can 表示请求和允许，以及猜测，而be able to 却无此用法。

　eg, Mr Smith can’t be at home.　 Can I carry your bag?

3. be able to 的过去式还有表示过去经过努力而做到的意思，而could 没有这种意思。

　eg, He studied hard and was able to pass the exam.

2. be able to 可用在不定式之后，而can却不能。

　eg, I hope to be able to go shopping with you on Sunday.

1. can是情态动词，无人称与数的变化。过去式是could.

be able to 可与情态动词连用，can却不能。

eg, I shall be able to speak English well.　

eg, Probably he may know the way. (放句首)

　 He is probably about 50 years old. (放在系动词后面)

　I probably didn’t try hard enough. (放在谓语前面)

　 It’ll probably rain. (放在助动词后面)

able adj. 1. 有能力的，能干的

　eg, My father is an able engineer.

2. 用于be able to 结构，后跟动词原形。

eg, Jim isn’t able to come tonight because he is ill.　

三、be able to 与can ：相同 点：两者后跟原形动词。

区别：

想象一下你们未来的学校、教室，写一篇短文介绍你们未来的学校、教室或未来的你。题目自拟。