-어야
-아야/어야: Only If — The Necessary Condition
Only if / when that condition is met — a connective that makes the first clause a necessary condition for the second.
How to form it
| When | Form | Example |
|---|---|---|
| Stem vowel is ㅏ or ㅗ | -아야 | 가다 → 가야 / 오다 → 와야 |
| Any other vowel / 이다 / 아니다 | -어야 | 먹다 → 먹어야 / 읽다 → 읽어야 |
| 하다 (hada) verbs | -해야 | 노력하다 → 노력해야 |
| Stronger ‘only if’ feel | -아야만 / -어야만 | 가야만 / 해야만 |
-아야 / -어야 links a necessary condition: first this, then that can happen.
Sejong’s own unit line is the cleanest example:
열심히 노력해야 목표를 이룰 수 있어요.
You have to work hard (only then) can you reach the goal.우리말샘 lists -아야 / -어야 as connectives where the first clause is the condition for the second. Classroom English often lands on only if or you have to … in order to ….
Forms
Same vowel decision as 해요체 and -어야 되다:
| Stem | Ending | Example |
|---|---|---|
| ㅏ / ㅗ | -아야 | 가야, 와야, 좋아야 |
| Other / 이다 | -어야 | 먹어야, 읽어야, 학생이어야 |
| 하다 | -해야 | 해야, 노력해야 |
지금 출발해야 제시간에 도착해요.
돈이 있어야 살 수 있어요.
건강해야 여행을 가요.Not the same as -어야 되다
| Form | Job |
|---|---|
| -아/어야 + second clause | necessary condition connective |
| -아/어야 되다/하다 | have to (obligation predicate) |
가야 돼요. I have to go. (stops there)
가야 친구를 만나요. Only if I go will I meet my friend.Learners who only know obligation glue 돼요 onto every -어야. If a real second clause follows, you are on this page — not stuck inside must.
Only if ≠ if
| Ending | Job |
|---|---|
| -으면 -으면 | if / when |
| -아야 / -어야 | necessary condition / only if |
| -아도 / -어도 -어도 | even if |
가면 만나요. If I go, I’ll meet them.
가야 만나요. I meet them only if I go.
가도 못 만나요. Even if I go, I can’t meet them.-어야 often pairs with ability talk like -을 수 있다 — only if X, can Y — exactly the unit title’s shape.
Stronger -어야만
-아야만 / -어야만 sharpens the only if feel. Recognise it; do not over-stack it when plain -어야 already does the job.
Plans and goals
Marriage plans, New Year resolutions, “things I must do first” — this unit’s speaking tasks live here:
저축해야 여행을 가요.
서로 이해해야 결혼 이야기를 해요.Ask: must the first thing be true for the second to happen? If yes, -아야/어야. If you only need soft if/when, stay with -으면. If you mean have to with no follow-up clause, use -어야 되다.
Do not confuse it with
Taught alongside this
On the jabi learning path, this appears in 열심히 노력해야 목표를 이룰 수 있어요 (You can achieve your goal if you work hard.) — Intermediate Korean 1, Unit 3, on the theme of plans and wishes. These come with it:
Words used above
Quick check
No sign-up, no score saved — just see if it stuck.
1. In 노력해야 목표를 이룰 수 있어요, what is -어야 doing?
2. How does 가야 돼요 differ from 가야 도착해요?
3. 가야 vs 가면 for ‘only if you go’?
Common questions
Is every -어야 sentence ‘have to’?
No. Have-to usually needs eoya-doeda. Bare -아야/어야 is a connective: condition first, result second.
How is this different from -으면?
eumyeon sets a condition. -어야 often implies that condition is *necessary* — only if / you have to do X for Y to happen.
What about -어도?
eodo is even-if concession. -어야 is the opposite energy: the condition must hold, not be brushed aside.
Should I learn -어야만?
Useful to recognise — it sharpens ‘only if.’ Do not force it into every sentence; plain -어야 already carries the necessary-condition feel.
Seen in the wild
Lessons where this pattern showed up in real Korean — news, slang, drama lines.
