# 英语初级 · 第 7 周 Day 3｜义务三兄弟

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**今天学什么**

前两天的句子都在"问"，今天开始"说要求"。must、have to、need to 中文都能译成"必须、得、需要"，但一个偏主观、一个偏规定、一个偏实际需要，否定形式的意思还完全相反。这三个词是看合同、听医嘱时最常出现的语法，用错 mustn't 会把"不必"说成"禁止"。学完你能写 8 句义务表达并录音。

## 一、今日任务

| 环节 | 时长 | 具体动作 | 产出 |
| --- | --- | --- | --- |
| 1 三词辨义 | 8 min | 三个词各写一句，句后标"谁要求的"：我要求 / 规定要求 / 事情需要 | 3 句对照 |
| 2 记规则 | 8 min | 抄下面五条规则，重点标 mustn't 与 don't have to 的意思差别 | 规则卡 1 张 |
| 3 替换操练 | 12 min | 每个词换 3 个动词说，先说 must sign / must pay / must leave，再换 have to、need to | 口头 9 句 |
| 4 写 8 句 | 12 min | must 3 句、have to 3 句、need to 2 句；其中必须有 1 句否定、1 句过去 | 8 句书面稿 |
| 5 录音 | 5 min | 遮稿连说 8 句，回听只查一处：must 后面有没有多 to | 1 段录音 |

合计 45 分钟。第 1 步的"谁要求的"这一栏是今天的核心。中文说"我必须去"时，听话人分不清是"我自己觉得必须"还是"公司规定"，英文靠 must 和 have to 把这个区别标出来。你能说清谁提的要求，选词就不会错。

第 4 步要求写一句否定、一句过去，是因为这两个位置最容易错：否定会撞上 mustn't 和 don't have to 的陷阱，过去会撞上"must 没有过去式"这条。提前写一次，比考试时现场想快得多。

只有 30 分钟的人，第 3 步每个词减到 1 句，第 4 步照写 8 句。三个词的差别靠写出来才记得住，只靠看规则第二天就糊。

## 二、核心词汇

| 单词 | 音标 | 词性 | 中文释义 | 高频搭配 | 例句与翻译 |
| --- | --- | --- | --- | --- | --- |
| must | /mʌst/（≈马斯特·短） | 情态动词 | 必须（主观） | must sign | You must sign here. 你必须在这里签字。 |
| have to | /ˈhæv tə/ | 情态短语 | 不得不（客观规定） | have to pay | I have to pay a deposit. 我得付押金。 |
| need to | /ˈniːd tə/ | 情态短语 | 需要 | need to check | We need to check the contract. 我们需要核对合同。 |
| sign | /saɪn/（≈赛恩） | 动词 | 签字 | sign a contract | Please sign at the bottom. 请在底部签字。 |
| rule | /ruːl/（≈鲁尔·长） | 名词 | 规定；规则 | the rules of the building | The rule is simple: no noise after ten. 规定很简单：十点后不许吵闹。 |
| allow | /əˈlaʊ/（≈厄劳·轻） | 动词 | 允许 | allow pets | The landlord doesn't allow pets. 房东不许养宠物。 |
| notice | /ˈnəʊtɪs/（≈诺提斯·短） | 名词 | 通知 | give one month's notice | You must give one month's notice. 你必须提前一个月通知。 |
| deadline | /ˈdedlaɪn/（≈戴德莱恩） | 名词 | 截止日期 | meet the deadline | The deadline is Friday. 截止日期是周五。 |

记词方法：must、have to、need to 三个不算"生词"，要靠对比记。做一个三列小表，左边写场景，中间写选哪个词，右边写理由：房东指着合同说签字——must；公司规定九点上班——have to；合同条款要逐条看——need to。场景和词绑在一起，比背中文释义牢。

sign、rule、allow、notice、deadline 五个是"合同词"，看租约时几乎每段都有。sign 是动词也是名词（招牌），今天只记动词；notice 除了"通知"，在租房语境里还有"提前告知期"的意思，give one month's notice 是退租时的标准说法，先记住整个短语，不必拆开分析。

allow 的用法要顺带记一下：allow + 名词（allow pets），不能说 allow to keep pets。这个词今天不展开，见到能懂就行。

再补一句使用频率的提醒：真实生活里 have to 比 must 出现得多得多。母语者说"我得走了"是 I have to go，很少说 I must go，因为 must 听起来像下命令或者写规章。所以你的默认选项应该是 have to，只有在明确表达"我要求你"或者"我下定决心"时才用 must。这条经验能让你说的话立刻自然一截。

读合同的时候还有一个小陷阱：must 的主语可以是物。The tenant must pay the rent on the first. 主语是人；The contract must be signed before Friday. 主语是合同，用被动。今天不要求你会写被动，但看到 must be done 这种形式不要慌，它还是"必须"，只是动作落在了东西身上。

## 三、发音/语法点

**must、have to、need to：主观、客观、需要**

1. must + 动词原形，表示说话人自己认为必须：You must sign here. 是"我要求你签"，不是"法律要求"。
2. have to + 动词原形，表示外部规定或客观情况逼着你做：I have to pay a deposit. 是"规定如此，我没办法"。主语三单用 has to，过去用 had to。
3. need to + 动词原形，表示事情本身需要做：We need to check the contract. 不是谁命令，而是不检查就会出问题。
4. must 没有过去式，也没有将来式。过去用 had to，将来用 will have to。不能说 musted，也不能说 will must。
5. 否定差别最大：mustn't 是"禁止、不许"，don't have to 是"不必、可以不做"。don't need to 与 don't have to 同义。

| 错误 | 正确 | 原因 |
| --- | --- | --- |
| You must to sign here. | You must sign here. | must 后面直接跟原形，不加 to |
| I musted pay the deposit. | I had to pay the deposit. | must 没有过去式，过去用 had to |
| You don't must smoke here. | You mustn't smoke here. | must 的否定是 mustn't，不借 don't |
| You mustn't come tomorrow.（想说不必） | You don't have to come tomorrow. | mustn't 是禁止，意思正好相反 |
| She have to sign the contract. | She has to sign the contract. | 三单用 has to |

发音提示：must 在句子里通常弱读成 /məst/，只有强调时才读足 /mʌst/；have to 连读成 /ˈhæftə/，听起来像一个词 hafta，不要一个词一个词地念成 have-to；need to 里的 d 和 t 相遇，实际读成 /ˈniːtə/。这三处连读不练，听力里就听不出对方在说"必须"。

常见错误再补三条：①把 must 当成"万能否定"，该用 don't have to 的地方用 mustn't，把"你不必来"说成"你不许来"；②need 后面漏 to，说成 I need check the contract，这是中国学生最高频的丢词；③把 have to 的疑问句说成 Have you to pay?，现代口语用 Do you have to pay?。

还有一个隐蔽的错：把 must 和 have to 叠在一起说 You must have to sign here。两个词只能留一个，选哪个看"谁提的要求"。另外 had to 的否定是 didn't have to（当时不必），不要说 hadn't to，后者在口语里几乎不出现。

## 四、句型/对话

1. You must sign here. 你必须在这里签字。
2. I have to pay a deposit. 我得付押金。
3. We need to check the contract. 我们需要核对合同。
4. Do I have to pay now? 我现在就得付吗？
5. You mustn't smoke in the flat. 公寓里不许抽烟。
6. You don't have to decide today. 你今天不必做决定。
7. He has to leave before twelve. 他得在十二点前离开。
8. We had to wait two days. 我们当时等了两天。

替换练习：把下面的动词换进三个架子，每换一次说完整句。

| 架子 | 换 1 | 换 2 | 换 3 |
| --- | --- | --- | --- |
| You must ___. | sign here | pay today | leave now |
| I have to ___. | pay a deposit | work on Saturday | wait outside |
| We need to ___. | check the contract | buy a lamp | call the agency |

看房现场的四句连说（念三遍，把 must 和 have to 的差别读出来）：

The landlord says, "You must sign here." 房东说："你必须在这儿签字。"
I have to pay one month's rent as a deposit. 我得付一个月租金当押金。
We need to check the contract before we sign. 签字前我们需要核对合同。
You don't have to decide today. 你今天不必做决定。

## 五、练习

**A 词汇（6 题）**

1. 填词：You must ______ here, next to your name.
2. 填词：The ______ for the deposit is Friday.
3. 选词（allow / notice）：The landlord doesn't ______ pets in the flat.
4. 中译英：我必须今天交押金。
5. 填词：We got a ______ from the landlord yesterday.
6. 改错：He must to go now.

**B 语法（5 题）**

1. 选词（must / have to）：I ______ wear a uniform at work. It's a company rule.
2. 填否定：You ______ smoke here. It's not allowed.
3. 填否定：You ______ come tomorrow. Friday is fine.
4. 改过去：I ______ (must) leave early yesterday.
5. 改错：She have to sign the contract.

**C 听说与写作（2 题）**

1. 写 8 句：must 3 句、have to 3 句、need to 2 句，其中必须有 1 句否定、1 句过去，然后遮稿录音。
2. 口头说 3 条你所在公司、学校或小区的规定（用 have to / mustn't），再说 2 条你自己给自己定的规矩（用 must / need to），共 5 句。

## 六、参考答案

**A**

1. sign —— 签字用 sign，next to your name 是提示位置。
2. deadline —— 截止日期是 deadline，for 后面接事项。
3. allow —— allow + 名词，不加 to；notice 是通知，意思不通。
4. I must pay the deposit today. —— 说话人自己认定的必须，用 must；today 放句末。
5. notice —— get a notice 是"收到通知"，notice 作名词。
6. He must go now. —— must 后面直接跟原形，to 是多余的。

**B**

1. have to —— 句子里明说是 company rule，外部规定用 have to。
2. mustn't —— "不许"是禁止，用 mustn't，不用 don't have to。
3. don't have to —— "不必"用 don't have to；用 mustn't 会变成"禁止来"。
4. had to —— must 没有过去式，过去用 had to。
5. She has to sign the contract. —— 三单主语用 has to。

**C**

1. 参考：You must show your ID at the door. / I must call my mother tonight. / We must be quiet after ten. / I have to pay the rent on the first. / She has to work on Saturday. / We had to wait for the landlord. / We need to buy a lamp. / You don't have to pay in cash. 检查点：must 后无 to，过去句用 had to，否定句意思与 mustn't 不冲突。
2. 参考：We have to keep the music down after ten. / You mustn't park in front of the building. / Students have to show their cards. / I must finish this book this week. / I need to call the agency tomorrow. 五句里 mustn't 与 don't have to 不能混用。如果想把"公司规定"说得更清楚，可以在句尾加 It's a rule.，一句话就把客观性交代完了。

## 七、今日输出与自查

- [ ] 产出文件：义务表达_第07周Day03.m4a，时长 60—90 秒。
- [ ] 8 句齐全：must 3 句、have to 3 句、need to 2 句，含 1 句否定、1 句过去。
- [ ] 正确率：must / have to / need to 后面全部是动词原形，错误 ≤ 1 处。
- [ ] 能口头说清 mustn't（禁止）与 don't have to（不必）的区别，各举一例。
- [ ] 错词本新增 2 条：notice、deadline，各写音标、搭配、例句。

## 八、明日预告

Day 4 换场景：从房子转到身体。12 个症状词（headache、fever、cough、sore throat 等），三个句型 I have a headache. / My back hurts. / I'm allergic to...，写 10 句并录音。今天学的 need to 明天会直接用到——I need to see a doctor. 睡前把那 8 句再听一遍，重点听 have to 的连读有没有读成"哈夫图"。