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)

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

  I go to school and (then) study.

• 집에 와서 잤어요.

  chip·e wa·sŏ chat·ssŏ·yo.jip·e wa·seo jat·sseo·yo.chip·e wa·sŏ chat·ssŏ·yo.cip·ey wa·se cat·sse·yo.

  I came home and slept.

• 친구를 만나서 영화를 봐요.

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

The first clause can also express the cause or reason for the second clause. In this context, it translates to "because" or "so".

• 배가 아파서 병원에 가요.

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

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

• 날씨가 좋아서 산책해요.

  nal·ssi·ga cho·a·sŏ san·chʰæk·hæ·yo.nal·ssi·ga jo·a·seo san·chaek·hae·yo.nal·ssi·ga cho·a·sŏ san·ch'aek·hae·yo.nal·ssi·ka co·a·se san·chayk·hay·yo.

  The weather is good, so I take a walk.

• 바빠서 못 갔어요.

  pa·bba·sŏ mot kat·ssŏ·yo.ba·bba·seo mot gat·sseo·yo.pa·ppa·sŏ mot kat·ssŏ·yo.pa·ppa·se mot kat·sse·yo.

  I was busy, so I couldn't go.

04

Important Rules

1. No Past Tense in the First Clause

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 no·rat·ssŏ·yo.eo·je chin·gu·reul man·na·seo no·rat·sseo·yo.ŏ·je ch'in·gu·rŭl man·na·sŏ no·rat·ssŏ·yo.e·cey chin·ku·lul man·na·se no·lat·sse·yo.

  Yesterday I met a friend and played. (Correct)

• 어제 친구를 만났어서 놀았어요.

  ŏ·je chʰin·gu·rŭl man·nat·ssŏ·sŏ no·rat·ssŏ·yo.eo·je chin·gu·reul man·nat·sseo·seo no·rat·sseo·yo.ŏ·je ch'in·gu·rŭl man·nat·ssŏ·sŏ no·rat·ssŏ·yo.e·cey chin·ku·lul man·nat·sse·se no·lat·sse·yo.

  (Incorrect usage of past tense marker)

2. No Commands or Suggestions

When used to express a reason ("because"), you cannot end the sentence with a command ("do this") or a suggestion ("let's do this").

• 비가 와서 집에 있어요.

  pi·ga wa·sŏ chip·e it·ssŏ·yo.bi·ga wa·seo jip·e it·sseo·yo.pi·ga wa·sŏ chip·e it·ssŏ·yo.pi·ka wa·se cip·ey it·sse·yo.

  It is raining, so I am at home. (Correct)

• 비가 와서 집에 있으세요.

  pi·ga wa·sŏ chip·e i·ssŭ·se·yo.bi·ga wa·seo jip·e i·sseu·se·yo.pi·ga wa·sŏ chip·e i·ssŭ·se·yo.pi·ka wa·se cip·ey i·ssu·sey·yo.

  (Incorrect: "Because it is raining, please stay home" is not allowed with this form.)