-아/어야

How It Works

Examples (5)

1. 숙제를 다 해야 놀 수 있어요.

   You have to finish all your homework to be able to play.

   Word by Word: Homework all must do can play.

   This shows that finishing homework is the necessary condition that must be met to be able to play. The first clause (숙제를 다 해야) is a prerequisite for the second clause (놀 수 있어요).

2. 날씨가 좋아야 소풍을 갈 거예요.

   We'll go on a picnic only if the weather is good.

   Word by Word: Weather must be good picnic will go.

   Here, -아/어야 is used with an adjective (좋다) to set a condition. Good weather is the prerequisite for the picnic.

3. 열심히 공부해야 시험에 합격할 수 있어요.

   You must study hard to be able to pass the exam.

   Word by Word: Diligently must study exam can pass.

   This demonstrates the 'necessary condition' usage with a 하다 verb. Studying hard (열심히 공부해야) is the prerequisite for being able to pass the exam.

4. 돈이 있어야 집을 살 수 있죠.

   You can only buy a house if you have money, of course.

   Word by Word: Money must exist house can buy, right.

   This example emphasizes the 'only if' meaning. Having money is the absolute requirement.

5. 매일 약을 먹어야 병이 나아요.

   You have to take the medicine every day for the illness to get better.

   Word by Word: Every day medicine must eat sickness gets better.

   This sentence shows a clear cause-and-effect relationship based on a necessary action.

Common Mistakes

• Confusing the necessary condition of -아/어야 with the general condition of -면 (if).

  Different Meaning일찍 일어나면 기차를 놓치지 않을 거예요. (This is okay, but weak if it's a strict requirement.)

  Better일찍 일어나야 기차를 놓치지 않을 거예요.

  -면 just means 'if'. 'If you wake up early, you won't miss the train.' It's a general statement. -아/어야 means 'only if'. 'Only if you wake up early will you not miss the train.' It implies that waking up early is a requirement and the only way to ensure you catch it.

• Incorrectly conjugating 하다 verbs.

  Not Quite운동하어야 건강해져요.

  Better운동해야 건강해져요.

  All verbs ending in 하다, like 운동하다, 공부하다, and 일하다, always conjugate to 해야 when used with this pattern.

Learn This First

To express 'should/must', you need to understand verb conjugation.

• Basic verb conjugation

  This conditional pattern requires conjugating verbs with 아/어야.

Related Patterns

• -아/어야 되다/하다Have to, Must

  This is the most common application of -아/어야, specifically used to express obligation or necessity ('must', 'have to'). -아/어야 is the conditional part, and 하다/되다 completes the meaning of obligation.

• -(으)면If, When

  Both express a condition, but -면 ('if') is for a general or hypothetical condition, while -아/어야 is for a necessary condition ('only if'). -아/어야 is much stronger and implies no other alternative.

• -아/어도 되다May, Be Allowed to

  This pattern means 'may' or 'it is okay to', expressing permission. It's the conceptual opposite of -아/어야 하다/되다, which expresses obligation. One tells you what you must do, the other tells you what you are allowed to do.

Learn Next

Patterns that build on this one.

• -아/어야 되다Have to, Must
• -아/어야겠다I Should, I Need to

Words in This Pattern