[Grammar] -(아/어/여)야 하다/되다 have to

-(아/어/여)야 되다 means ‘should, must, have to’ in English. You can also use 하다 instead of 되다, 하다 is a little bit formal than 되다. The conjugation is

verb stem ends with 아, 오 + 아야 하다/되다 
verb stem ends with other than  아/오 + 어야 하다/되다 
verb stem ends with 하 + 여야 하다/되다 => 해야 하다/되다 


지금 집에 가야 돼요.  I have to go home now.
오늘 일을 많이 해야 돼요.  I have to do a lot of work today.
이 약을 먹어야 돼요.  I have to take this medicine.
새 핸드폰을 사야 돼요.  I have to buy a new cell phone.
물을 많이 마셔야 돼요.  You(we, I) should drink a lot of water.
이 편지를 오늘 꼭 보내야 돼요. I must send this letter by today.
집을 청소해야 돼요. I have to clean the house.
너무 피곤해요. 집에서 쉬어야 돼요. I am so tired. I have to rest at home.
한국어로 일기를 써야 돼요. (click here to study 으 drop verb) I should write diary in Korean.
많이 걸어야 돼요. (click here to study ㄷ irregular verb) You(we, I) have to walk a lot.

Then how to say ‘you should not do’? It is -(으)면 안 되다. (click here to study)

You can listen to the audio file by clicking here. 


[Grammar] 반말 Casual form, informal form

When we make conversations, we have to consider four different ways of speech situations. First is situation, which is the occasion is formal or informal. Formal situation 격식체(1) is written, meetings, announcement or newspaper etc. Informal situation 비격식체(2) is normal conversations between family, friends or co-workers.

And we also have to consider who are the listeners. When you talk to elders or boss, you should use ‘polite speech 존댓말(3)’.  On the other hand, when you talk to your friends(the same age) or younger people who are very close to you, you can use ‘casual speech 반말(4)’.

Informal polite (비격식체 존댓말)


Informal casual(비격식체 반말)


Formal polite(격식체 존댓말)


Formal casual(격식체 반말


In this post, we are going to learn ‘반말 the causal endings’.  I divided 반말 as two types of endings for casual speech(반말) which are ‘formal situation(격식체)’ and ‘informal situation(비격식체)’.

Informal casual(비격식체 반말) is easy, you can just drop -요 from polite speech 아/어/여요, so the ending for casual speech is 아/어/여. For example, 어디에 가요? -> 어디에 가? , 뭐 해요? -> 뭐 해?  

Formal casual(격식체 반말) are more complicated.  They are different endings for different sentences. 

1. Statement : verb+는다/ㄴ다, adjective+다 (past tense: 았/었/였다, future tense: -을 것이다=을 거다)
For example,

  present past future
Polite 갑니다 갔습니다 갈 겁니다
Casual 간다 갔다 갈 것이다=갈 거다

2. Question : verb/adjective+냐? or 니?

  present past future
Polite 갑니까? 갔습니까? 갈 겁니까?
Casual 가냐? or 가니? 갔냐? or 가니? 갈 거냐?/갈 거니?

3. Suggestion : verb + 자

  present past future
Polite 갑시다 x x
Casual 가자 x x

4. Command/request : verb + 아/어/여라

  present past future
Polite 가십시오 x x
Casual 가라 x x


5. Nouns : When you speak to someone with the casual form, you are suppose to call someone’s name.(we are not allowed to call someone’s name if they are older than us).  Instead of ㅇㅇㅇ 씨, you can add -아 or -야 after their names.  For example,

민성 씨 => 민성아 (-아 is for the name ending with a consonant)
주아 씨 => 주아야 (-야 is for the name ending with a vowel)

6. Answer :

네 -> 어 예-> 응
아니요-> 아니 아닙니다-> 아니다



Please do not use 반말 to elders or people who you just meet. You can only use 반말 to people who are friends(the same age), younger people who are very close to you and family.