-(으)시-: Raising the Person You Are Talking About

Korean politeness runs in two independent directions, and most learners meet only one of them at first.

Raising the listener — the sentence ending: 해요, 합니다
Raising the subject — -(으)시-, inside the verb

They work separately, which produces something English has no equivalent for: you can be casual with the person in front of you while being formal about the person you are discussing.

Building it

Vowel → -시-
Consonant → -으시-
ㄹ → drop the ㄹ, then -시-

가다   →  가시다   →  가세요
읽다   →  읽으시다 →  읽으세요
살다   →  사시다   →  사세요      ← ㄹ drops
하다   →  하시다   →  하세요

-(으)세요 is simply what this becomes in the 해요체 ending — 가시어요 contracted. Which is why the two look so similar and why learners often meet 세요 first without knowing what is inside it.

Order matters

The pieces stack in a fixed sequence:

stem + -(으)시- + tense + ending

가 + 시 + 었 + 어요   →  가셨어요     ✅
갔으세요                              ✗

Honorific first, then tense. Always.

The part that surprises people

You use it about someone even when speaking casually to someone else.

부장님께서 가셨어. — The boss left. (said to a friend)

The ending 어 is 반말 — casual, because you are talking to a friend. The 셨 raises the boss, because the sentence is about him.

Both relationships are tracked at once. English picks one register per sentence; Korean runs two channels.

Never about yourself

제가 가세요.    ✗
제가 가요.      ✅

Elevating your own actions is a clear error and reads as self-important. When you want to be humble about yourself, Korean uses a different mechanism entirely — humble verbs like 드리다, 뵙다, 여쭙다.

께서

The honorific subject particle, replacing 이/가:

선생님께서 오세요.
아버지께서 말씀하셨어요.

It usually travels with -(으)시-. In casual speech people often keep 이/가 and let the verb ending carry the honour on its own — 선생님이 오세요 is extremely common.

Honorific nouns

A few nouns have elevated forms, and they pair with -(으)시-:

연세가 어떻게 되세요? — How old are you? (to an elder)
성함이 어떻게 되세요? — May I have your name?

Both of those are worth memorising whole. 나이가 몇이에요 to an elder is a small but noticeable misstep, and 연세 fixes it in one word.