Connective Suffix '서'

01

Formation

• If the verb stem ends in the vowels ㅏ (a) or ㅗ (o), add -아서 (a·sŏa·seoa·sŏa·se).
• If the stem ends in any other vowel, add -어서 (ŏ·sŏeo·seoŏ·sŏe·se).
• Verbs ending in 하다 (ha·daha·daha·daha·ta) change to 해서 (hæ·sŏhae·seohae·sŏhay·se).

02

Usage 1: Sequence (And Then)

The suffix -서 (sŏseosŏse) can indicate that the action in the first clause happens before the action in the second clause. The two actions are tightly connected; the second action usually takes place at the location reached in the first action. This is very common with motion verbs like 가다 (ka·daga·daka·daka·ta) - to go and 오다 (o·dao·dao·dao·ta) - to come.

• 학교에 가서 공부해요.

  hak·gyo·e ga·sŏ gong·bu·hæ·yo.hak·gyo·e ga·seo gong·bu·hae·yo.hak·gyo·e ga·sŏ gong·bu·hae·yo.hak·kyo·ey ka·se kong·pu·hay·yo.

  I go to school and (then) study.

• 집에 와서 잤어요.

  chib·e wa·sŏ jass·ŏ·yo.jib·e wa·seo jass·eo·yo.chib·e wa·sŏ jass·ŏ·yo.cib·ey wa·se cass·e·yo.

  I came home and slept.

• 친구를 만나서 영화를 봐요.

  chʰin·gu·rŭl man·na·sŏ yŏng·hwa·rŭl bwa·yo.chin·gu·reul man·na·seo yeong·hwa·reul bwa·yo.ch'in·gu·rŭl man·na·sŏ yŏng·hwa·rŭl bwa·yo.chin·ku·lul man·na·se yeng·hwa·lul pwa·yo.

  I meet a friend and watch a movie.

03

Usage 2: Reason (Because/So)

Besides linking actions in sequence, -서 (sŏseosŏse), added to the stem as -아서 (a·sŏa·seoa·sŏa·se) or -어서 (ŏ·sŏeo·seoŏ·sŏe·se), can make the first clause the cause or reason for the second, translating as "because" or "so". This meaning has rules of its own, such as its use in thanks and apologies and the ban on commands after it; they are covered in Indicating a Reason with '서'.

• 배가 아파서 병원에 가요.

  pæ·ga a·pʰa·sŏ byŏng·won·e ga·yo.bae·ga a·pa·seo byeong·won·e ga·yo.pae·ga a·p'a·sŏ byŏng·wŏn·e ga·yo.pay·ka a·pha·se pyeng·wen·ey ka·yo.

  My stomach hurts, so I am going to the hospital.

• 날씨가 좋아서 산책해요.

  nal·ssi·ga jo·a·sŏ san·chʰæ·kʰæ·yo.nal·ssi·ga jo·a·seo san·chae·kae·yo.nal·ssi·ga jo·a·sŏ san·ch'ae·k'ae·yo.nal·ssi·ka co·a·se san·chay·khay·yo.

  The weather is good, so I take a walk.

• 바빠서 못 갔어요.

  pa·ppa·sŏ mot gass·ŏ·yo.ba·bba·seo mot gass·eo·yo.pa·ppa·sŏ mot gass·ŏ·yo.pa·ppa·se mot kass·e·yo.

  I was busy, so I couldn't go.

04

Important Rules

1. No Past Tense in the First Clause

This holds for both meanings of -서 (sŏseosŏse), sequence and reason. Even if the sentence refers to the past, you do not add the past tense marker to the verb with -서 (sŏseosŏse). The tense is determined solely by the final verb of the sentence.

• 어제 친구를 만나서 놀았어요.

  ŏ·je chʰin·gu·rŭl man·na·sŏ nor·ass·ŏ·yo.eo·je chin·gu·reul man·na·seo nor·ass·eo·yo.ŏ·je ch'in·gu·rŭl man·na·sŏ nor·ass·ŏ·yo.e·cey chin·ku·lul man·na·se nor·ass·e·yo.

  Yesterday I met a friend and played. (Correct)

• 어제 친구를 만났어서 놀았어요.

  ŏ·je chʰin·gu·rŭl man·nass·ŏ·sŏ nor·ass·ŏ·yo.eo·je chin·gu·reul man·nass·eo·seo nor·ass·eo·yo.ŏ·je ch'in·gu·rŭl man·nass·ŏ·sŏ nor·ass·ŏ·yo.e·cey chin·ku·lul man·nass·e·se nor·ass·e·yo.

  (Incorrect usage of past tense marker)

2. Commands and Suggestions: Sequence Only

In its sequence meaning, -서 (sŏseosŏse) can lead into a command or a suggestion: first go somewhere, then do something there.

• 학교에 가서 공부하세요.

  hak·gyo·e ga·sŏ gong·bu·ha·se·yo.hak·gyo·e ga·seo gong·bu·ha·se·yo.hak·gyo·e ga·sŏ gong·bu·ha·se·yo.hak·kyo·ey ka·se kong·pu·ha·sey·yo.

  Go to school and study (there).

In its reason meaning it cannot: 비가 와서 집에 있으세요. (pi·ga wa·sŏ jib·e iss·ŭ·se·yo.bi·ga wa·seo jib·e iss·eu·se·yo.pi·ga wa·sŏ jib·e iss·ŭ·se·yo.pi·ka wa·se cib·ey iss·u·sey·yo.) is wrong. A reason for a command or a suggestion takes (으)니까 ((ŭ)ni·kka(eu)ni·gga(ŭ)ni·kka(u)ni·kka) instead, as Indicating a Reason with '서' explains.