在英语学习中，"be able to" 是一个非常实用的短语，用来表示“能够做某事”。它和 "can" 有些相似，但用法上有一些区别。"be able to" 更加正式，常用于强调完成某件事情的能力，尤其是在过去、将来或否定句中。

下面是一些使用 "be able to" 的例句，帮助你更好地理解和掌握它的用法：

1. I was able to finish my homework before dinner.

我能在晚饭前完成作业。

2. She is able to speak three languages fluently.

她能流利地说三种语言。

3. We were not able to go to the concert because of the bad weather.

因为天气不好，我们没能去听音乐会。

4. He will be able to start his new job next week.

他下周就能开始新工作了。

5. They are able to solve the problem by themselves.

他们能够自己解决这个问题。

6. Did you manage to call your mom yesterday?

你昨天有没有成功给妈妈打电话？

7. Even though it was difficult, I was able to pass the exam.

尽管很难，我还是通过了考试。

8. The firefighters were able to save all the people from the burning building.

消防员们成功地从着火的大楼里救出了所有人。

9. If you study hard, you will be able to achieve your goals.

如果你努力学习，你就能实现你的目标。

10. I’m not sure if I’ll be able to come to the party.

我不确定我是否能来参加聚会。

通过这些例句可以看出，"be able to" 在不同时间状语下可以灵活使用，表达出“有能力做某事”的意思。掌握这个短语不仅能提高你的英语表达能力，还能让你在写作和口语中更加自然、地道。

如果你正在学习英语，不妨多尝试用 "be able to" 来造句，这样可以帮助你更深入地理解它的用法和含义。