Lesson 20
By the end of this lesson, you will be constructing sentences using -아/어/여 [-a/eo/yeo] + -야 되다/하다 [-ya doe-da/ha-da] to say things such as “I have to go to work” or “You should buy it.”
To use this ending, take the verb stem and add -아/어/여 PLUS -야 되다 or -야 하다.
Conjugation
verb stem + -아/어/여 + -야 되다/하다
Ex)
자다 [ja-da] = to sleep
자 + -아/어/여 + -야 되다/하다
→ 자 + -아 + -야 되다/하다
(-아 is chosen because 자 ends with a vowel.)
→ 자야 되다/하다 [ja-ya doe-da/ha-da] (Drop the -아 because it is the 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
(-어 is chosen because 쓰 does not end in ㅏ or ㅗ.)
→ 써야 되다/하다 [sseo-ya doe-da/ha-da] (쓰 + 어 together change to 써)
→ 써야 되다 and 써야 하다 mean the same thing.
Conjugation
- verb stems ending in vowels ㅏ or ㅗ + -아야 되다/하다
- verb stems ending in other vowels + -어야 되다/하다
- 하 + -여야 되다/하다
However, it is more important to understand WHY -아/어/여야 되다/하다 means “to have to” or “should”.
To understand this better, look at the two parts separately:
- -아/어/여 + -야
This means “only when _____ is done” or “only when you do _____”.
- 되다 or 하다
되다 means “to be done” or “to be possible”, and 하다 means “to do” something.
Therefore, when putting 1 and 2 together, it takes the meaning of “only when you do _____, it works”, “only when you do this, everything is alright”, or “only if _____ is done, it is okay”. Thus, -아/어/여야 되다/하다 takes the meaning of “to have to” or “should”.
Q: What is the difference between 하다 and 되다 here?
A: The only difference is that using 되다 is more common in colloquial situations.
Sample Sentences
집에 가야 돼요. [ji-be ga-ya dwae-yo.]
= I have to go home.
저는 뭐 해야 돼요? [jeo-neun mwo hae-ya dwae-yo?]
= What should I do?
언제까지 여기에 있어야 돼요? [eon-je-kka-ji yeo-gi-e i-sseo-ya dwae-yo?]
= Until when should I be here?
누구한테 줘야 돼요? [nu-gu-han-te jwo-ya dwae-yo?]
= Who should I give this to?
어디에서 사야 돼요? [eo-di-e-seo sa-ya dwae-yo?]
= Where should I buy it?