-어서

• 여서 (-yeoseo) — used after 하다 (hada) verbs and adjectives

First attested in the Seokbo sangjeol (釋譜詳節 / 석보상절), 1447, as Middle Korean 어〮셔〮 (Yale: -é-syé), from Middle Korean 어〮 (Yale: -é, infinitive suffix) + 셔〮 (Yale: -syé, location postposition). The postposition is from the infinitive of the verb 이시다〮 (Yale: ìsìtá, “to be at”).

It was uncommon in the fifteenth century but increasingly became more widespread.[1]

• (SK Standard/Seoul) IPA^(key): [ʌ̹sʰʌ̹]
• Phonetic hangul: [어서]

어서 • (-eoseo)

1. so, since: a suffix used to express cause, reason.

   미안, 아기가 시끄러워서 잘 안 들려...

   Mian, agi-ga sikkeureowoseo jal an deullyeo...

   Sorry, my kid's being noisy so I can't hear you well.

   많이 먹어서 배가 아파졌다.

   Mani meogeoseo bae-ga apajeotda.

   I ate too much so I got a stomachache.

2. and then: a suffix used to indicate that two or more connected actions happen in a sequential order; the first clause usually establishes the state, position, location, or the object of the second clause.

   미연아, 누워서 밥을 먹지 마라!

   Miyeon-a, nuwoseo bab-eul meokji mara!

   Miyeon, don't eat lying down!

   (literally, “Miyeon, don't lie down and then eat!”)

   철수는 도서관에 가서 공부를 시작했어요.

   Cheolsu-neun doseogwan-e gaseo gongbu-reul sijakhaesseoyo.

   Cheolsu went to the library and then started studying (at the library).

   라면을 끓여서 먹었어.

   Ramyeon-eul kkeuryeoseo meogeosseo.

   I made ramyeon and then ate it.

   공원에서 친구를 만나서 영화를 보러 갔다.

   Gong'won-eseo chin'gu-reul mannaseo yeonghwa-reul bo-reo gatda.

   I met up with my friend at the park and then went to watch a movie (with them).

• For vowel harmony, contractions, and allomorphy, see 아/어/여 (-a/eo/yeo).
• 어서 (-eoseo) cannot be used with the tense markers 겠 (-get-) and 었 (-eot-) in the standard language, but this is still found in colloquial speech.
• When in the sense of so, since, 어서 (-eoseo) cannot be followed by imperative or propositive clauses.
• The words 반갑다 (ban'gapda), 감사하다 (gamsahada), 고맙다 (gomapda), 좋다 (jota), 죄송하다 (joesonghada), and 미안하다 (mianhada) commonly follow the 어서 (-eoseo) clause.