[Grammar] 반말 Plain 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 TV news etc. Conversational situation 비격식체(2) is normal conversations between family, friends or co-workers etc.

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 ‘plain speech 반말(4)’.

Conversational polite (비격식체 존댓말)
Conversational plain(비격식체 반말)
Formal polite(격식체 존댓말)Statement: verb/adjective+(스)ㅂ니다
Question: verb/adjective+(스)ㅂ니까?
Suggestion: verb+(으)ㅂ시다
Command: verb+(으)십시오
Noun : noun+입니다
Formal plain(격식체 반말Statement: verb+ㄴ/는다, adjective+다
Question: verb/adjective+냐?/니?
Suggestion: verb+자
Command: verb+아(어/여)라

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

Conversational plain(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, 뭐 해요? -> 뭐 해?, 뭐 했어요?-> 뭐 했어?, 뭐 할 거예요?-> 뭐 할 거야?

More example,
지금 공부해요. -> 지금 공부해.
어제 뭐 했어요? -> 어제 뭐 했어?
다음 주에 학교에 갈 거예요?-> 다음 주에 학교에 갈 거야?
저는 이민성이에요. -> 나는 이민성이야.
오랜만이에요. -> 오랜만이야.

Formal plain(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). We often use this form for writing journals, talking to young people or friends in a formal way. 
For example,

present past future
Polite 갑니다 갔습니다 갈 겁니다/겠습니다.
Casual 간다 갔다 갈 것이다=갈 거다/겠다

For example, 
지난 주에 날씨가 너무 안 좋았습니다. -> 지난 주에 날씨가 너무 안 좋았다.  
내일 학교에 갑니다.(formal polite) -> 내일 학교에 간다. 
지금부터 샌드위치를 만들겠습니다. -> 지금부터 샌드위치를 만들겠다. 
저 이제 집에 갑니다. -> 나 이제 간다. 

2. Question : verb/adjective+냐? or 니?. sounds more soft and friendly than,  Korean men use 냐 more than women. We use this for asking questions between friends and to people who are way younger than us and know them very well. For example, 40 year old uncle asks something about his 10 year old nephew. or two very close friends.

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

For example,
민수 씨가 지금 어디에 있습니까? -> 민수 지금 어디에 있냐?  / 민수 지금 어디에 있니?
밥 먹었습니까? -> 밥 먹었냐? / 밥 먹었니?
내일 무엇을 할 겁니까? -> 내일 뭐 할 거냐? / 내일 뭐 할 거니?

3. Suggestion : verb + 자

present past future
Polite 갑시다 x x
Casual 가자 x x

For example,
내일 공항에 같이 갑시다. -> 내일 공항에 같이 가자.
밥 먹읍시다. -> 밥 먹자.

4. Command/request : verb + 아/어/여라

present past future
Polite 가십시오 x x
Casual 가라 x x

For example,
이쪽으로 가십시오. -> 이쪽으로 가라.
음식을 드십시오. -> 음식을 먹어라.
안녕히 주무십시오. -> 잘 자라.

5. Nouns : Noun+이다 is “formal plain” form.
For example,
저는 김준성입니다.(formal polite) -> 나는 김준성이다. (formal plain).

6. Names : 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 met. You can only use 반말 to people who are friends(the same age), younger people who are very close to you like family.