Learn Korean (TTMIK)

Lesson 20

In this lesson, we are going to take a look at how to say that you “have to” or “should” do something in Korean. The construction itself is quite simple to understand. You take the verb stem of a verb and add the part (a verb ending) that makes the sentences take the meaning of “have to” or “should”.

to have to, should, must

= verb stem + -아/어/여 + -야 되다/하다

Examples:

자다 [ja-da] = to sleep

자 + -아/어/여 + -야 되다/하다

--> 자 + “-아” + -야 되다/하다 (You choose “-아” because 자 ends with the vowel “ㅏ”)

--> 자야 되다/하다 (You then drop the -아 because it’s the same same as “ㅏ”)

--> 자야 되다 and 자야 하다 are the same thing.

쓰다 [sseu-da] = to use, to write

쓰 + -아/어/여 + -야 되다/하다

--> 쓰 + “-어” + -야 되다/하다 (You choose “-어” because 쓰 doesn’t end in “ㅏ” or “ㅗ”)

--> 써야 되다/하다 (쓰 + 어 together change to ‘써’)

--> 써야 되다 and 써야 하다 mean the same thing.

So the construction is basically:

1. verb stems ending in vowels ‘ㅏ’ or ‘ ㅗ’ + -아야 되다/하다

2. verb stems ending in other vowels + -어야 되다/하다

3. 하 + -여야 되다/하다

one of the three above.

But it is more important to understand WHY -아/어/여야 되다/하다 means “to have to” or “should”.

In order to understand this, we can look at the structure in two separate parts.

1. -아/어/여 + -야

This part means “only when _____ is done” or “only when you do _____”.

2. 되다 or 하다

되다 means “to be done” or “to be possible” and 하다 means “to do” something.

So if you put 1 and 2 together, it takes the meaning of “only when you do _____, it works” or “only if _____ is done, it’s okay.” Therefore -아/어/여야 되다/하다 takes the meaning of “to have to” or “should.”

What is the difference between 하다 and 되다 here?

- The only difference is that using 되다 is more common in colloquial situations.

Sample sentences

1. 집에 가야 돼요. [ji-be ga-ya dwae-yo.]

= I have to go home.

2. 저는 뭐 해야 돼요? [jeo-neun mwo hae-ya dwae-yo?]

= What should I do?

3. 언제까지 여기에 있어야 돼요? [eon-je-kka-ji yeo-gi-e i-sseo-ya dwae-yo?]

= Until when should I be here?

4. 누구한테 줘야 돼요? [nu-gu-han-te jwo-ya dwae-yo?]

= Who should I give this to?

5. 어디에서 사야 돼요? [eo-di-e-seo sa-ya dwae-yo?]

= Where should I buy it?