안녕하세요, 여러분! (Hello, everyone!) 잘 지냈어요? In this post, you'll learn how to express "should" or "must" in Korean. 한국어 공부를 열심히 해야 돼요! (You should study Korean hard!) And I'll help your Korean learning journey! Let's begin 😊!
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1. V아/어/여야 되다(하다) Grammar
"아/어/여야 되다" is short form of 아야 되다, 어야 되다, 여야 되다. "아/어/여야 하다" is short version of 아야 하다, 어야 하다, 여야 하다. Since they are too long to write like that, Korean teachers including me use the shortened versions. Some people also use "어야 되다" or "어야 하다" as well.
Anyway, this "아/어/여야 되다" or "아/어/여야 하다" can be attached to a verb to show "should" or "must" in a sentence. They are the same. But in daily conversations, 되다 is more frequently used than 하다. On the other hand, in writing, you will see 하다 more often. Of course, you can switch them.
I have to study.
= 저는 공부를 해야 돼요.
= 저는 공부를 해야 해요.
You can use this expression to explain your obligation. You can also use it to give an order to a listener. In this case, you have to watch out. Your mom can command you to clean your room, but you can't order her to clean the house. It's the same in Korea. It is considered rude to give an order to older people.
저는 숙제를 해야 해요. I have to do my homework.
↳ You are simply explaining that you need to do your homework.
잭 씨, 숙제를 해야 해요! Jack, you have to do your homework!
↳ You are telling Jack what to do. If Jack is of a similar age as you, it is okay to use it.
(X) 사장님, 보고서를 내야 해요! Boss, you have to submit the report.
↳ You can't say to your boss like this! You can't put a burden on superiors. You'll need more indirect, beat-about-the-bush talking.
2. Conjugation Information
This ending consists of two parts, "아/어/여야" and "되다(하다)". I'll explain each part to you.
A. 아/어/여야
To decide from 아야, 어야, or 여야, what do you have to check? Will it be a final consonant or the last vowel? Yes, the answer is the last vowel. It is a recurring rule, so I recommend you to remember! When an ending starts with 아/어/여, you must check the last vowel! My other post explains the details well, so if you are curious, please click here to read more. I'll show you some examples with 돼요 form.
Regular Rules
If the last vowel is ㅏ or ㅗ, you will add 아야. If the stem ends 하, you will use 해야 after a noun part. Other than that, please 여야 to a verb stem!
가다 → 가야 돼요. I should go.
보다 → 봐야 돼요. I should see.
공부하다 → 공부해야 돼요. I should study.
숙제하다 → 숙제해야 돼요. I should do my homework.
먹다 → 먹어야 돼요. I should eat.
마시다 → 마셔야 돼요. I should drink.
Irregular Rules
The irregular Korean rules are very repetitive as well. If you want to master them, please check out my "Grammar Concepts" section.
걷다 → 걸어야 돼요. I should walk.
젓다 → 저어야 돼요. I should stir.
줍다 → 주워야 돼요. I should pick it up.
쓰다 → 써야 돼요. I should write.
B. 하다/되다
When you change 되다 into an informal present tense, you will choose from 아요 or 어요. The vowel of the stem 되 is "ㅚ". It is not ㅏ or ㅗ. So, we need to use regular rule number 3 and attach 어요 to it; 되어요. However, Korean people usually shorten this 되어요 to 돼요.
This 돼요 part is considered a tricky part even to Koreans. You may see "되요," while you are surfing the internet, but it is the wrong one. 돼 came from 되어, so it should be written 되어요 or 돼요.
하다 should be easy for you now if you study this far with me. The present tense of 하다 is 해요. So, to say I should go now, there are two possible sentences in Korean. 지금 가야 해요. or 지금 가야 돼요.
If you are curious about other 되다 conjugation read this section.
The informal endings
The past: 되 → 되 + 었어요 → 되었어요 or 됐어요 → Again, the short one 됐어요 is more often used in daily conversations.
The future/guess: 되 → It doesn't have the final consonant. Let's add ㄹ 거예요. → 될 거예요.
The formal endings
The present: 되다 → 되 → There is no final consonant. We need ㅂ니다. → 됩니다.
The past: 되 → No final consonant means 었습니다. → 되었습니다. → You can shorted it to 됐습니다.
The future/guess: 되 → No final consonant. You'll need ㄹ 것입니다. → 될 것입니다.
3. Sentence Information
A. Commonly used words
Since "어야 하다" or "어야 되다" shows an obligation and responsibility, it is often used with adverbs like 꼭 or 반드시. 꼭 and 반드시 mean surely, certainly, at any cost. So, they are emphasizing the meaning of 어야 하다/되다 expression.
12시까지 숙제를 내야 해요. I have to submit my homework by 12.
12시까지 꼭 숙제를 내야 해요. I must submit my homework by 12.
쓰레기는 반드시 쓰레기통에 버려야 해요! You must throw away trash in trash cans!
B. Negative form
There are two negative forms; "V지 않아야 되다" and "안 V어야 되다". The second one is more commonly used in daily conversation.
술을 마시지 않아야 돼요. = 술을 안 마셔야 돼요. You shouldn't drink alchol.
결석을 하지 않아야 돼요. = 결석을 안 해야 돼요. You shouldn't skip school.
4. Examples
1
내일 시험이 있어요. 열심히 공부해야 돼요.
I have a test tomorrow. I must study hard.
2
감기에 걸렸어요. 약을 먹어야 돼요.
I have a cold. I need to take my medicine.
↳ 약 is medicine. To say "take medicine," you can use the verb, 먹다(eat)! Even if it is a liquid type of medicine, people will still use 먹다 as the meaning of take.
3
Q: 약을 언제 먹어야 돼요? When should I take medicine?
A: 식사 후에 드세요. Take it after your meal.
↳ 식사 means 'a meal' or 'eating a meal'. 후 is after. So 식사 후 means "after having a meal." 드세요 came from the basic form 드시다. It is an honorific version word of 먹다. When you talk about yourself, you will always use the non-honorific form 먹다 but when you talk to somebody politely, you'd better use 드시다.
4
A: 가수가 되고 싶어요. I want to become a singer.
B: 그러면 노래를 연습해야 돼요. Then, you should practice singing.
↳ What do you want to be? 뭐가 되고 싶어요? What practice do you have to do? 뭐 해야 돼요?
5
A: 시청이 어디있어요? Where is the city hall?
B: 저기로 가면 돼요. Just go that way.
↳ You can often hear this expression when you give a direction. 저기 is a direction that is far from both the speaker and listener. Since it is a direction, the direction marker 로 is attached. If you want to learn more about it, please check my other post, (으)로.
5. Wrap-up & Worksheet: Should in Korean
You can tell an obligation by using "아/어/여야 돼요." or "아/어/여야 해요." expression. It can be translated as "should," "must", "need to," or "have to" in English. Please download the free printable PDF worksheet to practice these expressions.
마이 코리안 레슨과 함께 열심히 공부해야 돼요! You must study hard with My Korean Lesson! 😊👍 In the next lesson, you'll learn how to ask for permission.