Korean Grammar Bank

HOW TO SAY MUST IN KOREAN

Just like in English, ‘must’ in Korean can be used to express two things.

  • Obligation
  • Confirmation

In this lesson, we will look into the use of ‘must’ in Korean to express obligation.

EXPRESSING OBLIGATION

When expressing obligation, we use this form: ‘~야(만) 한다’ which is added to the verb subject to ‘must’. 

You may also use ~야 한다, or 야만 한다. Either way is acceptable.

For ‘~하다’ verb we remove ‘다, change ‘하’ to ‘해’, and add ‘~야(만) 한다.’

PATTERN

Verb + ~야(만) 한다

‘~하다’ VERBVERB MEANINGCONJUGATION
‘~야(만) 한다’		MEANING
공부를 하다To study 공부를 해야(만) 한다. You must study.
식사를 하다To have a meal 식사를 해야(만) 한다. You must have a meal.
운전을 하다To drive 운전을 해야(만) 한다. You must drive.

VERBS ENDING IN A VOWEL

For verbs ending with a vowel, the grammar rule is a little bit more complicated, as there is more than one variation of the ending.

PATTERN

Verb + ~야(만) 한다

Let’s take a look at some examples below.

VERBS ENDING WITH‘ㅏ’MEANINGCONJUGATIONMEANING
자다To sleep 너는 자야(만) 한다. You must sleep.
사다To buy 너는 사야(만) 한다. You must buy it.
가다To go 너는 가야(만) 한다. You must go.

Check out our Creating Adverbs page to learn more useful grammar points.

Verbs ending in ‘ㅜ’

As for verbs ending in ‘ㅜ’, this is the general rule below:

PATTERN

Verb + ~어야(만) 한다

VERBS ENDING WITH ‘ㅜ’MEANINGCONJUGATIONMEANING
뛰다To run 너는 뛰어야(만) 한다. You must run.
주다To give 너는 그것을 줘야(만) 한다.
→ ‘주어’ is contracted to ‘줘’		You must give it.
치우다To arrange 너는 방을 치워야(만) 한다
→ ‘치우어’ is contracted to ‘치워’		You must arrange your room.

Verbs ending in ‘ㅗ’

For verbs ending in ‘ㅗ’, this is how to change them:

PATTERN

Verb + ~아야(만) 한다

VERBS ENDING WITH ‘ㅗ’MEANINGCONJUGATIONMEANING
보다To see 너는 그것을 봐야(만) 한다
→ ‘보아’ is contracted to ‘봐’		You must see it.
오다To come 너는 와야(만) 한다
→ ‘오아’ is contracted to ‘와’		You must come.

Verbs ending in ‘ㅣ’

Let’s see how we change verbs ending in ‘ㅣ’:

PATTERN

Change the verb ‘ㅣ’ to ‘ㅕ’, and add ‘~야(만) 한다.’

VERBS ENDING WITH ‘ㅣ’MEANINGCONJUGATIONMEANING
달리다To run 너는 달려야(만) 한다. You must run.
가리다To cover 그것은 가려야(만) 한다. You must cover it.
안기다To be hugged 그녀는 그에게 안겨야(만) 한다. She has to be hugged by him.

Verbs ending in ‘ㅡ’

And finally, let’s see what we do with verbs ending in ‘ㅡ’.

PATTERN

Remove ‘ㅡ’ and add ‘~아야(만) 한다.’

VERBS ENDING WITH ‘ㅡ’MEANINGCONJUGATIONMEANING
모으다To collect/save 너는 돈을 모아야(만) 한다. You must save money.
오르다To climb up 너는 산을 올라야(만) 한다. You must climb up the mountain

VERBS ENDING WITH A CONSONANT

Like with the vowel endings, consonant endings are also a bit complicated as they vary based on the different consonant endings.

The same rule is applied if the last syllable of the infinitive verb form contains the same vowel, regardless of whether the ending is a vowel or a consonant.

Ending with ‘ㅏ’ + consonant

Let’s see how that generally works for verbs that have a ‘ㅏ’ vowel in the last syllable and end with a consonant.

PATTERN

Verb + ~아야(만) 한다

VERBS ENDING WITH ‘ㅏ’MEANINGCONJUGATIONMEANING
팔다To sell 사과를 팔아야(만) 한다. We must sell the apples. 
살다To live 인생을 잘 살아야(만) 한다. We must live our lives well.
닫다To close 가게 문을 닫아야(만) 한다. We must close the store.

Ending with ‘ㅜ’ + consonant

Moving onto verbs ending with ‘ㅜ’ in the last syllable and with a consonant.

PATTERN

Verb + ~어야만 한다

VERBS ENDING WITH ‘’MEANINGCONJUGATIONMEANING
묻다To ask 모르는 것은 물어야(만) 한다. If you don’t know something, you must ask a question.
풀다To solve 숙제를 끝내기 위해 문제를 풀어야(만) 한다. You must solve the problem to finish the homework.
울다To cry 슬플때는 때때로 잊기위해 울어야(만) 한다. When we are sad, sometimes we must cry to let things go. 

The structure can get a bit confusing. Check out our sentence structure page for a quick refresher!

Ending with ‘ㅗ’ + consonant

As for verbs that end with ‘ㅗ’ in the last syllable and end with a consonant, here is what we do:

PATTERN

Verb + ~아야(만) 한다

VERBS ENDING WITH ‘ㅗ’MEANINGCONJUGATIONMEANING
몰다To herd/drive 양치기는 양떼를 몰아야(만) 한다. A shepherd must herd sheep.
뽑다To select/elect 우리는 다가올 선거를 위해 적합한 후보자를 뽑아야(만) 한다. We must select the right candidate for the upcoming election.

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Ending with ‘ㅣ’ + consonant

Verbs that end with ‘ㅣ’ in the last syllable and end with a consonant are generally conjugated like this:

PATTERN

Verb + ~어야(만) 한다

VERBS ENDING WITH ‘’MEANINGCONJUGATIONMEANING
입다To wear 저녁에는 외투를 입어야(만) 한다. In the evening, you must wear a jacket.
씹다To chew 밥을 먹을 때는 음식을 꼭꼭 씹어야(만) 한다. When eating, you must chew the food thoroughly.

Ending with ‘ㅡ‘ + consonant

And finally, the that verbs that end with ‘ㅡ’ in the last syllable and end with a consonant.

PATTERN

Verb + ~어야(만) 한다

VERBS ENDING WITH ‘ㅡ’MEANINGCONJUGATIONMEANING
만들다To make 일을 시작하기 전에 계획서를 만들어야(만) 한다. You must plan before starting the work.
읊다To recite 이 북클럽에서는 책에서 얻은 가장 좋아하는 구절을 읊어야(만) 한다. In this book club, you must recite your favourite phrase from a book.

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FAQs

What is must used for in Korean?

Just like in English, ‘must’ in Korean can be used to express 1) obligation and 2) confirmation.

What do we use when expressing obligation?

When expressing obligation in Korean, we use this form: ‘~야(만) 한다’ which is added to the verb subject to ‘must’. 

What to add for verbs ending in ‘ㅡ’ vowels?

We remove the ‘ㅡ’ and add ‘~아야(만) 한다.’

What to add to verbs ending in ‘ㅜ’ vowels?

We add ‘~어야만 한다’ to the verb.

What to add to verbs ending in consonants?

We use the same rule as for vowel endings: If the last syllable of the infinitive verb form contains the same vowel, the same rule is applied regardless of whether the ending is a vowel or a consonant.

Where can I find more free Korean resources?

Our Korean Grammar Bank has some fantastic free resources for you to check out.

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