jabi-으면 되다 / -으면 안 되다
-으면 되다: Enough If — and Must Not
It's fine if / you must not — permission-as-sufficiency and prohibition built on -(으)면.
How to form it
| When | Form | Example |
|---|---|---|
| Stem ends in a consonant (not ㄹ) — enough / fine if | -으면 되다 | 먹다 → 먹으면 되다 / 앉다 → 앉으면 되다 |
| Stem ends in a vowel or ㄹ — enough / fine if | -면 되다 | 가다 → 가면 되다 / 살다 → 살면 되다 |
| Prohibition (classroom pair) | -(으)면 안 되다 | 늦으면 안 돼요 / 먹으면 안 돼요 |
| Polite speech | -(으)면 돼요 / 안 돼요 | 신청만 하면 돼요 |
-으면 되다 and -으면 안 되다 are a pair: it’s fine if / that’s enough versus you must not.
약속 시간에 늦으면 안 돼요 — the Sejong unit title is the prohibition half. The positive half is just as common: 신청만 하면 돼요 — applying is enough.
The pair
| Pattern | Job | Example |
|---|---|---|
| -(으)면 되다 | fine if / doing X is enough | 이름만 쓰면 돼요 |
| -(으)면 안 되다 | must not | 늦으면 안 돼요 |
비밀번호만 알면 돼요. Knowing the password is enough.
여기서 뛰면 안 돼요. You mustn’t run here.
내일 오면 돼요. It’s fine if you come tomorrow.Flip 돼요 ↔ 안 돼요 and you flip the rule of the room.
Dictionary note (positive vs prohibition)
우리말샘 lists auxiliary 되다 with -으면 되다: the action or state being okay or desirable. Related permission notes also mention frames such as -어도 되다 and -어서는 안 되다.
Classroom Korean treats -으면 안 되다 as the everyday must not twin of -으면 되다. That prohibition frame is rock-solid in speech and textbooks; do not wait for a perfect matching auxiliary headword before using it. If you need a dictionary-anchored “mustn’t” cousin later, -어서는 안 되다 is the form the dictionary highlights more explicitly — different shape, same family of “not allowed.”
Not -어도 되다 (may)
| Form | Lean |
|---|---|
| -어도 되다 -아/어도 되다 | may / is it okay to…? |
| -으면 되다 | fine if / that will do |
들어가도 돼요? May I come in?
들어가면 돼요. Coming in is enough / you’re fine if you go in.English okay if covers both; Korean often picks by whether you are asking permission or stating a minimum.
Not -어야 되다 (must)
| Form | Lean |
|---|---|
| -어야 되다 -아/어야 되다 | have to |
| -으면 되다 | enough if |
| -으면 안 되다 | must not |
가야 돼요. I have to go.
가면 돼요. Going is fine / that’s enough.
가면 안 돼요. You mustn’t go.
안 가도 돼요. You don’t have to go. ← obligation removed, different frameMust, must not, don’t have to, and enough if are four different buttons. Do not map them all to English have to / can.
Beside plain -으면
-으면 only opens the condition. 되다 / 안 되다 adds the rule:
비 오면 취소해요 — result.
늦으면 안 돼요 — prohibition modality.
Quick check
Before you speak, pick the box:
- Minimum / that’ll do → -으면 되다
- Forbidden → -으면 안 되다
- Allowed to? → -어도 되다
- Obligated → -어야 되다
Do not confuse it with
Taught alongside this
In the Sejong course this appears in 약속 시간에 늦으면 안 돼요 — Sejong Korean 3A & 3B, Unit 1, on the theme of 모임. These come with it:
Words used above
Quick check
No sign-up, no score saved — just see if it stuck.
1. What does 신청만 하면 돼요 mainly mean?
2. Unit title 늦으면 안 돼요 — which job?
3. 가도 돼요 vs 가면 돼요?
Common questions
Is -으면 안 되다 in the dictionary as an auxiliary?
우리말샘 clearly lists auxiliary 되다 for -으면 되다 (okay/desirable if). The classroom pair -으면 안 되다 is everywhere in teaching and speech; the dictionary’s related notes highlight frames like -어서는 안 되다 more directly. Learn the pair from usage, and don’t force a missing headword.
How is this different from -어야 되다?
[[g:eoya-doeda]] is obligation — you have to. -으면 되다 is ‘it’s enough if / that will do.’ 가야 돼요 ≠ 가면 돼요.
How is this different from -어도 되다?
[[g:eodo-doeda]] is may / it’s allowed. -으면 되다 often answers ‘what’s the minimum?’ — 이것만 하면 돼요.
What about bare -으면?
[[g:eumyeon]] is just the conditional connective. The modality arrives when 되다 / 안 되다 follows.