语法点:情态动词 may / might / can / could (Permission & Possibility)
may、might、can、could 都是情态动词,后面接动词原形,主要有两种用法。一是请求许可:Can I…? 最随便,Could I…? 和 May I…? 更客气。二是表示可能性:may / might 表示“可能、也许”,might 比 may 语气更不确定;对已经发生的事作推测,用 may / might have + 过去分词。本课作者买票时用了三种问法,正好展示了这些情态动词的差别。
结构
| 用法 | 结构 | 例句 |
|---|---|---|
| 请求许可(随便) | Can I + 动词原形? | Can I return these two tickets? |
| 请求许可(客气) | Could I / May I + 动词原形? | May I have two tickets please? |
| 回答许可 | Certainly. / Yes, you can(may). / No, you can't. | 'Certainly,' the girl said. |
| 现在或将来的可能 | may / might + 动词原形 | The play may begin at any moment. |
| 对过去的推测 | may / might + have + 过去分词 | It may have begun already. |
| 否定 | may not / might not / can't / couldn't | It might not begin on time. |
课文中的例句
- [句 1] 'The play may begin at any moment,' I said. — may + 动词原形,表示现在或马上可能发生。
- [句 2] 'It may have begun already,' Susan answered. — may have + 过去分词,推测已经发生的事。
- [句 4] 'May I have two tickets please?' I asked. — May I…? 客气地请求许可。
- [句 8] 'Can I return these two tickets?' he asked. — Can I…? 较随便的请求许可。
- [句 11] 'Could I have those two tickets please?' I asked. — Could I…? 是 can 的委婉形式,不表示过去。
- [句 14] 'I might as well have them,' I said sadly. — might as well 是固定搭配,“不妨、只好”。
补充例句
- Could I have a ticket for next Wednesday's performance? 我可以买一张下周三演出的票吗?
- The ticket office may be closed now. 售票处现在可能关门了。
- Susan might have gone to the theatre already. 苏珊可能已经去剧院了。
易错点
- ❌ May I to have two tickets? → ✅ May I have two tickets? 情态动词后直接接动词原形,不加 to。
- ❌ It may began already. → ✅ It may have begun already. 推测过去发生的事要用 may have + 过去分词。
- ❌ Could I had those tickets yesterday? → ✅ Could I have those tickets? Could I…? 是客气请求,不是过去时;后面仍接动词原形。
- ❌ Can I return these tickets? — Yes, you may not. → ✅ Yes, you can. / No, you can't. 肯定回答不能和 not 连用,且回答应与问句情态动词呼应。