There are seven speech levels in Korean.
-ㅂ니다 and -습니다 are the ending suffix of Hasipsio-che
-ㅂ니다 is used after a verb or adjective which ends with vowel or ㄹ
-습니다 is used after a verb or adjective which ends with consonant except ㄹ
-다 is the ending suffix of Haera-che
-(어/아/여)요 and -에요 are the ending suffix Haeyo-che
-어요 is used after a verb or adjective of which final vowel is ㅓ, ㅕ, ㅜ, ㅡ, ㅣ, ㅐ, ㅔ, ㅖ, ㅞ, ㅚ, ㅟ, ㅢ
-아요 is used after a verb or adjective of which final vowel is ㅏ, ㅑ, ㅗ, ㅘ
-여요 is used after 하다 verb
-에요 is used after 이다 or 아니다
Hasipsio-che(Formality: high, Politeness: high)
is a common style of speaking. A conversation with a stranger will generally start out in this style and gradually fade into more and more frequent haeyo-che. It is used
between strangers at the start of a conversation
among male co-workers
by TV announcers
to customers
Haeyo-che(Formality: low, Politeness :high) is remarkable in that it is used both with higher level pronouns (namely, titles) as well as the middle level second person pronoun dangsin. It is used mainly:
In Korean phrasebooks for foreigners.
Between strangers, especially those older or of equal age.
Between female co-workers or friends.
Haera-che(Formality: high, Politeness :low) is generally called the "plain" style. It is used:
To close friends or relatives of similar age, and by adults to children.
In impersonal writing (books, newspapers, and magazines) and indirect quotations ("She said that...").
In grammar books, to give examples.
For example
with 여자이다,
나는 여자이다 is Haera-che
저는 여자에요 is Haeyo-che
저는 여자입니다 is Hasipsio-che
with 크다
집이 크다 is Haera-che
집이 커요 is Haeyo-che
집이 큽니다 is Hasipsio-che
with 작다
집이 작다 is Haera-che
집이 작아요 is Haeyo-che
집이 작습니다 is Hasipsio-che
with 먹었다
사과를 먹었다 is Haera-che
사과를 먹었어요 is Haeyo-che
사과를 먹었습니다 is Hasipsio-che
Refer to
https://en.wikipedia.org/wiki/Korean_speech_levels