Understanding Korean grammar is essential for effective communication, especially when expressing prohibitions or restrictions. One key structure used for this purpose is ‘~(으)면 안 되다’, which means “you shouldn’t” or “it’s not allowed” in English. This phrase is commonly used to prohibit actions, express rules, or give warnings in both formal and informal settings.
In this guide, we’ll break down the meaning, usage, and common mistakes related to ‘~(으)면 안 되다’, with plenty of examples to help you master it.
Contents
1. Definition
‘~(으)면 안 되다’ is a Korean grammar structure used to indicate that an action is not permitted or should not be done. It is often translated as “must not” or “should not” in English.
2. Form (Structure)
Structure: Verb/Adjective + (으)면 안 되다
- Verb/Adjective stems ending with ㅏ or ㅗ → -으면 안 되다
- Example (Verb): 잡다 → 잡으면 안 되다 (You must not catch.)
- Example (Verb): 찾다 → 찾으면 안 되다 (You must not find.)
- Example (Adjective): 좋다 → 좋으면 안 되다 (It must not be good.)
- Example (Adjective): 넓다 → 넓으면 안 되다 (It must not be wide.)
- Verb/Adjective stems ending with other vowels or ㄹ → -면 안 되다
- Example (Verb): 먹다 → 먹으면 안 되다 (You must not eat.)
- Example (Verb): 보다 → 보면 안 되다 (You must not see.)
- Example (Adjective): 슬프다 → 슬프면 안 되다 (It must not be sad.)
- Example (Adjective): 길다 → 길면 안 되다 (It must not be long.)
Note: For verbs/adjectives ending with ㄹ, the ㄹ is dropped before adding -면 안 되다.
- Example: 살다 → 사면 안 되다 (You must not live.)
- 놀다 → 노면 안 되다 (You must not play.)
- 멀다 → 머면 안 되다 (It must not be far.)
- 달다 → 다면 안 되다 (It must not be sweet.)
- 울다 → 우면 안 되다 (You must not cry.)
- 팔다 → 파면 안 되다 (You must not sell.)
This structure is used to express prohibition or strong advice against doing something.
| Type | Structure | Examples |
| Verb (Stem ends with ㅏ or ㅗ) | Verb Stem + -으면 안 되다 | 먹다 → 먹으면 안 되다 (You must not eat.) 앉다 → 앉으면 안 되다 (You must not sit.) |
| Verb (Stem ends with other vowels or ㄹ) | Verb Stem + -면 안 되다 | 가다 → 가면 안 되다 (You must not go.) 보다 → 보면 안 되다 (You must not look/watch.) |
| Adjective (Stem ends with ㅏ or ㅗ) | Adjective Stem + -으면 안 되다 | 작다 → 작으면 안 되다 (It must not be small.) 늦다 → 늦으면 안 되다 (It must not be late.) |
| Adjective (Stem ends with other vowels or ㄹ) | Adjective Stem + -면 안 되다 | 빠르다 → 빠르면 안 되다 (It must not be fast.) 길다 → 길면 안 되다 (It must not be long.) |
2. Meaning & Usage
(1) Prohibition or Rules:
Example: “여기에 주차하면 안 됩니다.”
(You must not park here.)
Example: “여름에 너무 더우면 안 돼요.”
(It must not be too hot in the summer.)
Example: “도서관에서 큰 소리로 떠들면 안 됩니다.”
(You must not speak loudly in the library.)
Example: “시험 중에 답을 서로 확인하면 안 돼요.”
(You must not check answers with each other during the test.)
(2) Asking for Permission (Question Form):
Politely ask if something is not allowed.
Example: “휴대전화를 사용하면 안 돼요?”
(Is it okay to use my phone?)
Example: “여기에서 신발을 벗으면 안 될까요?”
(Would it be okay to take off my shoes here?)
Example: “쓰레기를 조금 버리면 안 될까요?”
(Is it okay to throw away a little trash?)
Example: “이 방에 들어가면 안 돼요?”
(Is it okay if I enter this room?)
(3) Double Negative (Obligation):
When used as 안 A/V~으면/면 안 되다 or A/V~지 않으면 안 되다, it means “must do” or “have to do.”
Example: “숙제를 안 하면 안 돼요.”
(You must do your homework.)
Example: “음식이 신선하지 않으면 안 됩니다.”
(The food must be fresh.)
Example: “건강 검진을 정기적으로 안 받으면 안 돼요.”
(You must receive regular health checkups.)
Example: “회의 자료를 준비하지 않으면 안 됩니다.”
(You must prepare the meeting materials.)
3. Formal and Informal Variations
| Formality Level | Expression | Example |
| Formal | ~면 안 됩니다 | 여기에 쓰레기를 버리면 안 됩니다. (You must not throw trash here.) |
| Informal | ~면 안 돼 | 여기에 쓰레기를 버리면 안 돼. (You must not throw trash here.) |
- This expression is generally polite and widely used in everyday conversations, especially in public or social settings.
- The formal version ~면 안 됩니다 is more appropriate in professional or official contexts, while the informal ~면 안 돼 is suitable for casual conversations.
5. Common Mistakes & Tips
(1) Confusing Adjectives and Verbs:
Correct: 추우면 안 돼요. ✅ (You shouldn’t get cold / Don’t let yourself get cold)
Incorrect: 춥으면 안 돼요. ❌ – This is grammatically incorrect.
Incorrect: 춥다면 안 돼요. ❌ – Unnatural in this context.
(2) Double Negative Usage:
Understand that 안 A/V~으면 안 되다 or A/V~지 않으면 안 되다 is used for obligations, not prohibitions.
Example: 학생들이 준비를 안 하면 안 돼요. (Students must prepare.)
(3) Overuse of Formal Style in Casual Situations:
Using ~면 안 됩니다 with friends or family might feel too formal. Instead, use ~면 안 돼.
6. Practical Examples
Prohibition Examples
- Verbs:
- 여기에서 뛰면 안 돼요. (You must not run here.)
- 시험 시간에 휴대폰을 쓰면 안 됩니다. (You must not use your phone during the exam.)
- Adjectives:
- 여름에 너무 더우면 안 돼요. (It must not be too hot in the summer.)
- 공기가 나쁘면 안 됩니다. (The air must not be bad.)
Asking for Permission (Question Form):
- 창문을 열면 안 돼요? (Is it okay to open the window?)
- 강아지를 데려오면 안 될까요? (Would it be okay to bring my dog?)
Double Negative Examples (Obligation):
- 숙제를 안 하면 안 돼요. (You must do your homework.)
- 음식이 신선하지 않으면 안 됩니다. (The food must be fresh.)
7. Comparison with Other Prohibitive Expressions
| Expression | Meaning | Example |
| A/V~으면/면 안 되다 | You must not / It’s not allowed to… | 공기가 나쁘면 안 돼요. (The air must not be bad.) |
| 못 V | I cannot / I’m unable to… | 여기에서 사진을 못 찍어요. (I cannot take pictures here.) |
| V~지 마세요 | Please don’t… | 여기에서 사진 찍지 마세요. (Please don’t take pictures here.) |
8. Practice Exercises
Complete the sentences below using A/V~으면/면 안 되다:
- 도서관에서 _________. (크게 말하다)
- 여름에는 날씨가 _________. (너무 덥다)
- 이곳에 쓰레기를 _________. (버리다)
- 음식이 _________. (신선하지 않다)
- 시험 중에 _________. (핸드폰을 사용하다)
- 회사에서 _________. (늦게 출근하다)
- 공원에서 _________. (술을 마시다)
- 길을 _________. (막다)
- 수업 중에 _________. (잠을 자다)
- 밤에 _________. (시끄럽게 놀다)
9. Answers
- 크게 말하면 안 돼요.
- 날씨가 너무 더우면 안 돼요.
- 쓰레기를 버리면 안 돼요.
- 음식이 신선하지 않으면 안 돼요.
- 핸드폰을 사용하면 안 돼요.
- 늦게 출근하면 안 돼요.
- 술을 마시면 안 돼요.
- 길을 막으면 안 돼요.
- 잠을 자면 안 돼요.
- 시끄럽게 놀면 안 돼요.