无需：don't have to / needn't

要说某件事没有必要（你可以做，但不必做），用 don't have to、don't need to 或 needn't + 动词原形。

💡needn't 的用法像情态动词（不加 -s，不加 to）：He needn't come。need 作普通动词时要用 to 和 do：He doesn't need to come。不要把两者混在一起（不说 needn't to，也不说 doesn't need come）。

1. 某件事可做可不做——你想做就可以做

• You don't have to come with me. I can go alone.

  你不用陪我去。我可以自己去。

• It's Sunday tomorrow, so I don't have to get up early.

  明天是星期天，所以我不用早起。

2. 因为情况特殊，某人不必做某事

• Thu doesn't have to pay rent. She lives with her parents.

  阿秋不用付房租。她和父母住在一起。

• The test is open-book, so you don't need to learn the dates by heart.

  这次考试是开卷的，所以你不用背那些日期。

3. 告诉别人不必费心——礼貌又友好

• You don't have to bring anything. Just come!

  你什么都不用带。人来就行！

• You needn't worry. Everything is ready.

  你不用担心。一切都准备好了。

• You don't have to shout. I can hear you.

  你不用喊。我听得见。（其实是说：请别喊了）

4. 询问某件事是否必要

• Do I have to bring my passport? — No, you don't.

  我需要带护照吗？——不，不用。

• Do we need to book? — No, you don't need to. Just walk in.

  我们需要预订吗？——不，不需要。直接来就行。

这两个看起来很像，但意思完全不同：

• You don't have to pay for the drinks. They're free.

  饮料你不用付钱。是免费的。

• You mustn't park here. It's for ambulances only.

  你不能在这里停车。这是救护车专用的。

💡快速检验：如果后面可以加上“……不过你想做也可以”，就用 don't have to。如果你的意思是“这是禁止的”，就用 mustn't。

谈论过去时，用 didn't have to 或 didn't need to：当时没有必要。

• The bus was almost empty, so we didn't have to stand.

  公交车上几乎没人，所以我们不用站着。

• Lan didn't need to cook — her mum had made dinner.

  阿兰不用做饭——她妈妈已经做好晚饭了。

如果某件事已经做了，结果发现没有必要，英式英语可以用 needn't have + 过去分词。日常口语中，很多人干脆说 didn't need to。

• Oh, you needn't have bought milk — I got some this morning.

  哦，你本来不用买牛奶的——我今天早上买了。（你买了，但其实没必要）

• ✗You mustn't pay for the drinks. They're free.

  ✓You don't have to pay for the drinks. They're free.

  没有必要 → 用 don't have to；mustn't 表示禁止。

• ✗He don't have to work on Saturdays.

  ✓He doesn't have to work on Saturdays.

  he/she/it → doesn't。

• ✗She doesn't has to cook tonight.

  ✓She doesn't have to cook tonight.

  doesn't 后面用 have，不用 has。

• ✗You needn't to call me first.

  ✓You needn't call me first.

  needn't 后面不加 to。

• ✗You don't need bring anything.

  ✓You don't need to bring anything.

  don't need 后面要有 to。

• ✗We haven't to wait.

  ✓We don't have to wait.

  have to 的否定式要用 don't。