A2 · 초중급 챕터 9

Obligation and Necessity

3 총 규칙
32 예문
5 분
이 챕터의 규칙 빠른 연습

Chapter in 30 Seconds

Master the language of rules, duties, and essential choices to navigate daily life with confidence.

  • Distinguish between personal and external necessity.
  • Identify actions that are strictly forbidden.
  • Differentiate between prohibited acts and optional tasks.
Speak with authority and clarity on every obligation.

배울 내용

Let's explore how to talk about what's truly essential and what's forbidden! By understanding *Must* vs. *Have to* and *Mustn't*, you'll soon be able to clearly express rules, duties, and choices in all your conversations. You've got this!

Learning Objectives

By the end of this chapter, you will be able to:

  1. 1
    By the end you will be able to: Explain classroom or office rules clearly.

챕터 가이드

Overview

Mastering how to express what’s essential and what’s off-limits is a big step in your A2 English grammar journey. This chapter on English obligation and necessity isn't just about learning new words; it's about gaining the power to communicate clearly in everyday situations. Imagine being able to explain a rule, suggest an important action, or politely decline something without confusion.
That’s what we’ll achieve together!
You'll soon understand the subtle yet crucial differences between must and have to, allowing you to describe personal duties versus external rules effortlessly. We'll also tackle how to firmly state prohibitions using mustn't, and how to differentiate between things you absolutely cannot do and things you simply don't need to do with must not vs. need not.
By the end of this guide, you’ll feel confident expressing obligations, necessities, and prohibitions in all your conversations. This isn't just theory; it's practical language that you'll use constantly, whether you're at work, traveling, or just chatting with friends. You're ready to master these essential grammar points and speak with greater precision and confidence!

How This Grammar Works

Let's dive into the core of expressing obligation and necessity. The primary tools you'll use are must and have to, and it's key to understand their unique flavors. We use must when the obligation comes from *inside* you – it's a strong personal feeling, a recommendation you firmly believe in, or something you *personally* decide is necessary.
For example,
I must remember to call my parents today
(it's important *to me*). Remember, never use to directly after must.
On the other hand, have to is for obligations that come from *outside* you – external rules, laws, or requirements from others. Think of it as something you are *forced* or *required* to do. For instance,
Students have to wear a uniform at this school
(it's a school rule, not their personal choice).
It’s very common in everyday conversation.
When you need to say that something is strictly forbidden, prohibited, or a very bad idea, you'll use mustn't. This is a powerful negative command. If a sign says, "You mustn't touch the exhibits," it means touching them is absolutely not allowed.
It’s the strong negative form of must, meaning 'do not do this, it is forbidden.'
Finally, let's look at must not versus need not. While must not is simply another way to say mustn't (e.g.,
You must not interrupt the speaker
– it's forbidden), need not has a completely different meaning. Need not means that something is *not necessary*, and you have a choice.
It's the opposite of having an obligation. For example,
You need not bring a gift to the party, your presence is enough
means bringing a gift is optional, not required. Understanding these distinctions will make your English much clearer.

Common Mistakes

Here are a few common pitfalls to avoid:
  1. 1Using must to: This is a very common error.
✗ You must to study for the exam.
✓ You must study for the exam. (No to after must.)
  1. 1Confusing "mustn't with don't have to": They have opposite meanings. Mustn't is a prohibition; don't have to means no obligation.
✗ We mustn't get up early tomorrow. (This means it's forbidden to get up early, which is usually not what you mean!)
✓ We don't have to get up early tomorrow. (This means it's not necessary to get up early, we have a choice.)
  1. 1Using must for external rules instead of have to: While must can sometimes imply a rule, have to is the standard for external obligations.
✗ All passengers must show their passports at the border. (While technically understandable, have to is more natural for a formal rule.)
✓ All passengers have to show their passports at the border. (This clearly indicates an external requirement.)

Real Conversations

Here are a few examples of these grammar points in action:

1. A: I must remember to send that email before I leave work today. It's really important!

B

B

Yes, and we have to finish this project by Friday, or the client will be unhappy.

2. A: We're going to a museum. Remember, you mustn't run inside.

B

B

Okay, I understand. Do we have to stay together all the time, or can I look at different rooms?

3. A: I made too much food. You need not help me eat it all, but you're welcome to take some home if you like!

B

B

That's kind, but I must not eat too much sugar. I'm trying to be healthy.

Quick FAQ

Q

Can I use must for future obligations?

Yes, you can! For example,

I must go to the dentist next week.
However, have to is often more common and natural for future external obligations, like
I will have to work late tomorrow.

Q

What’s the negative form of have to?

The negative form of have to is don't have to (or doesn't have to for third person singular). It means there is no obligation. For example, "You don't have to come if you don't want to." This is very different from mustn't!

Q

Is must not exactly the same as mustn't?

Yes, they mean exactly the same thing: strict prohibition. Mustn't is simply the common contracted form, especially in spoken English.

Q

When should I use need not instead of don't have to?

They are very similar! Both express a lack of necessity or obligation. Need not can sometimes sound slightly more formal or emphatic than don't have to, but you can often use them interchangeably in A2 contexts.

Cultural Context

Native English speakers use have to far more frequently than must in everyday, informal conversation for obligations. Must often carries a stronger, sometimes more formal or dramatic tone, or expresses a very personal conviction. Mustn't is a strong prohibition and is always understood that way.
For softer prohibitions, speakers might use "shouldn't or can't." Regional differences are minimal in the core meaning, but the frequency of use might vary slightly.

주요 예문 (6)

1

I `must remember` her birthday this year!

올해는 그녀의 생일을 꼭 기억해야 해!

Must vs. Have to: 필요성에 대해 말하기
2

We `have to submit` our assignment by midnight.

우리는 자정까지 과제를 제출해야 해.

Must vs. Have to: 필요성에 대해 말하기
3

You mustn't post that photo without her permission.

그녀의 허락 없이 그 사진을 올리면 안 돼요.

금지된 행동: mustn't(~하면 안 된다) 사용법
4

We mustn't forget to cancel the subscription before the free trial ends!

무료 체험 끝나기 전에 구독 취소하는 걸 잊으면 안 돼요!

금지된 행동: mustn't(~하면 안 된다) 사용법
5

You must not post that photo of me without asking!

내 허락 없이 그 사진 올리면 안 돼!

Must Not 대 Need Not (금지 대 선택의 차이)
6

You needn't bring any food; I've already ordered pizza.

음식 가져올 필요 없어. 내가 이미 피자 시켰어.

Must Not 대 Need Not (금지 대 선택의 차이)

팁과 요령 (3)

💡

내부 vs. 외부

Must는 주로 화자의 개인적인 느낌이나 확신에서 오는 의무이고, have to는 외부 규칙, 사람, 또는 상황에서 오는 의무를 나타낸다는 걸 기억하세요. 예를 들어, 'I must study.'와 'I have to study.'는 뉘앙스가 달라요.
frontend.learn_grammar.from_rule: Must vs. Have to: 필요성에 대해 말하기
⚠️

'to' 함정 조심!

'mustn't to'는 절대 안 돼요. 'mustn't' 같은 조동사 다음에는 동사 원형이 바로 와야 해요. "You mustn't to go.« (X) 대신 »You mustn't go.«라고 해야 자연스러워요. »You mustn't to go."
frontend.learn_grammar.from_rule: 금지된 행동: mustn't(~하면 안 된다) 사용법
⚠️

'Mustn't'와 'Don't Have To' 헷갈리지 마세요!

'You mustn't come'은 '오지 마!' 하고 금지하는 거예요. 하지만 'You don't have to come'은 '안 와도 돼' 하고 선택권을 주는 거죠.
frontend.learn_grammar.from_rule: Must Not 대 Need Not (금지 대 선택의 차이)

핵심 어휘 (5)

obligation something you must do forbidden not allowed essential absolutely necessary duty a moral or legal task optional not required

Real-World Preview

book-open

At the Library

Review Summary

  • Subject + must/have to + verb
  • Subject + mustn't + verb
  • Subject + need not + verb

자주 하는 실수

Must is a modal verb and is followed by the base form of the verb without 'to'.

Wrong: I must to go now.
정답: I must go now.

We do not use 'do/don't' with 'must'. Use 'mustn't' for prohibition.

Wrong: You don't must go there.
정답: You mustn't go there.

Like must, need not is a modal and does not take 'to' before the main verb.

Wrong: You needn't to pay.
정답: You need not pay.

Next Steps

You have navigated the world of rules perfectly. Keep practicing, and these forms will become second nature to you!

Write a list of 5 rules for your dream country.

Continue to: Present Tenses: Simple, Continuous and Perfect

빠른 연습 (9)

외부 의무를 표현하는 문장을 고르세요.

올바른 문장을 고르세요:

✓ Correct! ✗ Not quite. Correct answer: She has to study for her exam.
시험공부는 일반적으로 과목을 통과하기 위한 외부 요구사항(학교/대학교에서)입니다.

frontend.learn_grammar.from_rule: Must vs. Have to: 필요성에 대해 말하기

빈칸에 올바른 형태를 채우세요.

You ______ share your password with strangers.

✓ Correct! ✗ Not quite. Correct answer: mustn't
'Mustn't'는 금지/안전 규칙에 사용돼요. 'Don't have to'를 쓰면 선택 사항이라는 뜻이 되어 위험하답니다!

frontend.learn_grammar.from_rule: 금지된 행동: mustn't(~하면 안 된다) 사용법

올바른 형태를 고르세요.

You ___ forget to lock the door when you leave.

✓ Correct! ✗ Not quite. Correct answer: mustn't
문을 잠그는 것은 필요한 안전 조치이므로, 잊지 말라는 것은 금지를 나타냅니다.

frontend.learn_grammar.from_rule: Must vs. Have to: 필요성에 대해 말하기

틀린 부분을 찾아 고치세요.

Find and fix the mistake:

You must not to forget your password.

✓ Correct! ✗ Not quite. Correct answer: You must not forget your password.
'must'와 같은 조동사 뒤에는 'to' 없이 동사 원형이 옵니다.

frontend.learn_grammar.from_rule: Must Not 대 Need Not (금지 대 선택의 차이)

의무가 없음을 나타내도록 빈칸을 채우세요.

The museum is free today, so you ___ pay for a ticket.

✓ Correct! ✗ Not quite. Correct answer: needn't
박물관이 무료이므로, 돈을 낼 필요가 없습니다. 'Needn't'는 의무가 없음을 나타냅니다.

frontend.learn_grammar.from_rule: Must Not 대 Need Not (금지 대 선택의 차이)

실수를 찾고 고치세요.

Find and fix the mistake:

She mustn't to use her laptop in the exam.

✓ Correct! ✗ Not quite. Correct answer: She mustn't use her laptop in the exam.
'mustn't' 뒤에 있는 'to'를 제거해야 해요. 조동사 다음에는 동사 원형이 바로 온답니다.

frontend.learn_grammar.from_rule: 금지된 행동: mustn't(~하면 안 된다) 사용법

엄격한 규칙에 맞는 문장은 무엇일까요?

병원 표지판에 이렇게 쓰여 있어요:

✓ Correct! ✗ Not quite. Correct answer: You mustn't smoke here.
병원에서의 흡연은 금지되어 있으므로, 금지를 나타내는 'mustn't' (must not)가 올바른 선택입니다.

frontend.learn_grammar.from_rule: Must Not 대 Need Not (금지 대 선택의 차이)

실수를 찾아 고치세요.

Find and fix the mistake:

I musted go to the dentist yesterday.

✓ Correct! ✗ Not quite. Correct answer: I had to go to the dentist yesterday.
Must는 의무를 나타내는 과거 시제가 없습니다. 과거의 필요성에는 had to를 사용합니다.

frontend.learn_grammar.from_rule: Must vs. Have to: 필요성에 대해 말하기

엄격한 규칙에 맞는 문장을 고르세요.

If you are in a library, which sentence is correct?

✓ Correct! ✗ Not quite. Correct answer: You mustn't talk loudly.
'mustn't' 다음에는 'to'나 '-ing' 없이 동사 원형을 써야 해요.

frontend.learn_grammar.from_rule: 금지된 행동: mustn't(~하면 안 된다) 사용법

Score: /9

자주 묻는 질문 (6)

핵심적인 차이점은 의무의 출처예요. Must는 내부적인 느낌이나 강한 확신을 표현하는 반면, have to는 외부 규칙, 법, 또는 상황에 의한 의무를 표현합니다. 예를 들어, 'I must tell you something important.' (내가 너에게 중요한 것을 꼭 말해야겠어 - 내 생각)와 'I have to tell you something important.' (너에게 중요한 것을 말해야 해 - 누가 시켰거나 상황상).
Must는 개인적인 의무, 강력한 추천, 또는 당신이 매우 중요하다고 느끼는 것을 표현할 때 가장 좋습니다. 예를 들어, 'I must call my parents today.' (오늘 부모님께 꼭 전화해야지 - 내 마음)처럼요.
둘 다 같은 의미지만, 'mustn't'는 말할 때나 비공식적인 글에서 줄여 쓰는 표현이에요. 'must not'은 격식 있고 좀 더 강조하는 느낌을 줘요.
아니요, 그건 실수예요. 'I mustn't go'라고 해야 해요. 조동사 뒤에는 'to'를 절대 쓰면 안 된답니다. "I mustn't go."
'Must not'은 무언가가 금지되었다는 뜻이고 (금지), 'Need not'은 무언가가 필수가 아니라는 뜻이에요 (의무 없음). 예를 들어, 'You must not enter'는 문이 잠겨서 들어갈 수 없다는 뜻이지만, 'You needn't enter'는 원하지 않으면 들어가지 않아도 된다는 뜻이에요.
네! 현대 영어에서는 'needn't'나 'need not'보다 'don't have to'가 훨씬 더 흔하게 쓰여요. 의미는 같아요.
이전 챕터
Connecting Ideas and Asking for Details
다음 챕터
Present Tenses: Simple, Continuous and Perfect
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