📌 Expressing Obligation in Korean: -아/어야 되다/하다

Do you know how to say “I have to do something” in Korean? The grammar pattern -아/어야 되다 or -아/어야 하다 is essential for expressing obligation or necessity. Whether you're talking about homework, rules, or life advice, this structure will come up all the time!

1. What Does -아/어야 되다/하다 Mean?

The structure -아/어야 되다 or -아/어야 하다 is used when you want to say:

“I must…”
“I have to…”
“You should…”

It's one of the most useful expressions for daily life, especially when talking about responsibilities, obligations, or advice.

2. How to Conjugate

Use the verb stem and attach the right connector based on vowel harmony:

If the verb stem ends in ㅏ or ㅗ → attach -아야
Other vowels → attach -어야
하다 verbs → become -해야

Then, add 되다 (doeda) or 하다 (hada):

Examples:
가다 → 가야 되다 (gaya doeda) → I have to go
먹다 → 먹어야 하다 (meogeoya hada) → I have to eat
공부하다 → 공부해야 돼요 (gongbuhaeya dwaeyo) → I must study

3. Useful Everyday Examples

Korean (한글)	Pronunciation (로마자)	English
약을 먹어야 해요.	yageul meogeoya haeyo	I have to take medicine.
내일까지 숙제를 해야 돼요.	naeilkkaji sukjereul haeya dwaeyo	I must do the homework by tomorrow.
일찍 자야 돼요.	iljjik jaya dwaeyo	You should sleep early.
운전면허가 있어야 해요.	unjeon myeonheoga isseoya haeyo	You need to have a driver’s license.
한국에서는 신발을 벗어야 돼요.	hangugeseoneun sinbareul beoseoya dwaeyo	You have to take off your shoes in Korea.

4. 되다 vs 하다: Is There a Difference?

Technically, -아/어야 하다 and -아/어야 되다 are interchangeable in most situations.

하다 is a bit more formal or bookish
되다 is slightly more conversational

Both are accepted in speaking and writing, so don’t worry too much about the difference — just pick one and stay consistent.

5. 💡 Did You Know?

💡 In Korea, social obligations and personal responsibilities are a big part of daily life. That's why you'll often hear “해야 돼요” or “해야죠” (I must, of course!) — it's not just grammar, it reflects Korean cultural values around diligence, respect, and harmony.

💡 In schools, students are often reminded:
“공부 열심히 해야 돼요!” (gongbu yeolsimhi haeya dwaeyo!) → “You must study hard!” It’s a phrase every Korean student has heard growing up.

💡 Even street signs use this grammar! Example: “운전 중에는 휴대폰을 사용해서는 안 됩니다.” (While driving, you must not use your phone.)

6. 🧠 Self-Learning Tips

📝 Make a list of 5 things you must do today. Write them in Korean using -아/어야 되다!
🎧 Watch a Korean drama or show and listen for “해야 돼” or “해야 해.” Count how many times you hear it!
📱 Use flashcards to mix obligation verbs with time expressions (e.g., 내일까지, 오늘 꼭, 지금 당장)

Quick Quiz:
Translate: "I must go home early."
➡ 정답: 일찍 집에 가야 돼요. (iljjik jibe gaya dwaeyo)

7. 🎓 Learn More Korean with Me

Want to make your Korean more natural? Or practice these expressions in conversation? 👉 Book a lesson with me on italki — we’ll use real-life situations to master essential grammar like this!