在英语学习中，情态动词是表达语气和推测的重要工具。通过这些词，我们可以更准确地传递说话者的主观态度或对事情可能性的看法。以下是情态动词用于推测时的一些常见用法及例句，帮助你更好地掌握这一知识点。
一、表示可能性
1. can/could
- 现在时：用来表示不太确定的可能性。
- Example: He can be at the office now. (他可能在办公室。)
- 过去时：表示对过去事件的可能性猜测。
- Example: She could have missed the bus. (她可能错过了公交车。)
2. may/might
- 表示可能性较低的情况，通常比“can”更正式一些。
- Example: It may rain tomorrow. (明天可能会下雨。)
- Example: He might not come to the party. (他可能不会来参加聚会。)
3. must
- 表示非常高的可能性，接近肯定。
- Example: You must be tired after such a long trip. (经过这么长的旅途，你一定很累。)
- Example: The book must be in the library. (这本书一定在图书馆里。)
二、表示推测（过去）
1. could have + 过去分词
- 表示对过去发生的事情进行推测，但事实未知。
- Example: They could have gone to the beach yesterday. (他们昨天可能去了海滩。)
2. might have + 过去分词
- 与“could have”类似，但语气更弱一些。
- Example: She might have forgotten the appointment. (她可能忘记了约会。)
3. must have + 过去分词
- 表示对过去事件的高度推测，接近肯定。
- Example: He must have studied hard for the exam. (他一定为考试努力复习了。)
三、练习题
以下是一些练习题，帮助你巩固所学知识：
1. The traffic is so heavy today. He ____________ be late for work.
A) can
B) may
C) must
2. I saw his car outside, but he ____________ not be home yet.
A) can
B) may
C) must
3. She ____________ have missed the train because she arrived late.
A) can
B) might
C) must
4. It ____________ rain later. Let’s take an umbrella just in case.
A) can
B) may
C) must
5. The meeting ____________ have started by now.
A) can
B) might
C) must
答案：
1. B) may
2. B) may
3. B) might
4. B) may
5. C) must
通过以上总结和练习，相信你能更加熟练地运用情态动词进行推测。继续多加练习，你会发现自己的英语表达能力有了显著提升！
