语法点:needn't 与 needn't have done (need)
need 作情态动词时,主要用于否定句和疑问句,表示“不必、没有必要”。needn't + 动词原形谈论现在或将来:You needn't be so rude.(你没必要这么粗鲁。)needn't have done 谈论过去:本来没有必要做,可是已经做了,常带责备或后悔的语气:You needn't have said that.(你本来不必说那句话的。)注意 needn't 和 mustn't 完全不同:mustn't 是“禁止、不可以”,needn't 只是“没必要”。need 也可以作实义动词,这时用 don't need to / didn't need to。
结构
| 用法 | 结构 | 例句 |
|---|---|---|
| 现在/将来不必 | needn't + 动词原形 | You needn't wait for me. |
| 过去做了不必做的事 | needn't have + 过去分词 | You needn't have bought so many hats. |
| 疑问 | Need + 主语 + 动词原形? | Need I remind you? — No, you needn't. / Yes, you must. |
| 实义动词 | don't / didn't need to + 动词原形 | We didn't need to buy a new hat. |
| 禁止(对比) | mustn't + 动词原形 | We mustn't buy things we don't need. |
课文中的例句
- [句 2] 'You needn't be so rude about it,' my wife answered as she looked at herself in the mirror. — needn't + 原形,指现在没必要这样做。
- [句 5] 'We mustn't buy things we don't need,' I remarked suddenly. — mustn't 表示“不可以”,与 needn't 的“不必”形成对比。
- [句 7] 'You needn't have said that,' my wife answered. — needn't have done:话已经说出口,但本不必说,带责备语气。
- [句 8] 'I needn't remind you of that terrible tie you bought yesterday.' — needn't + 原形,表示“没必要提醒”,实际上是在暗示提醒。
补充例句
- You needn't wear a hat in the shop. 你在店里不必戴帽子。
- He needn't have waited for half an hour; the shop was closed. 他本来不必等半个小时的,商店关门了。
- Need I buy a new tie for the party? — No, you needn't. 我需要为聚会买条新领带吗?——不,不必。
易错点
- ❌ You needn't to say that. → ✅ You needn't say that. needn't 是情态动词,后面直接接动词原形,不加 to。
- ❌ You needn't said that. → ✅ You needn't have said that. 谈过去“本不必做却做了”,要用 needn't have + 过去分词。
- ❌ We needn't buy things we don't need.(想表达“不可以买”) → ✅ We mustn't buy things we don't need. needn't 是“不必”,mustn't 才是“不可以、禁止”。
- ❌ She doesn't need buy a hat. → ✅ She doesn't need to buy a hat. need 作实义动词时要用 need to。