Grammar
-았/었/였고
Meaning
Beginner-at/eot/yeotgo
A past-tense connective ending (-았고/-었고/-였고) that links two clauses, each already marked for past tense, to mean 'did A, and then did B' or 'A happened, and B also happened.' Used to report two related past events or facts one after another.
Form
Attach 았고 to stems whose last vowel is ㅏ or ㅗ, 었고 to all other vowel stems, and 였고 to 하다 verbs (하다 → 했고). Each clause keeps its own past-tense marker before 고: 가다 → 갔고, 먹다 → 먹었고, 공부하다 → 공부했고. This differs from plain -고, where tense is usually shown only once, at the end of the sentence.
Examples
삼성이 이겼고 KT가 졌습니다.
Samsung won, and KT lost.
어제는 비가 왔고 오늘은 맑아요.
It rained yesterday, and today it's clear.
저는 예전에 학생이었고 지금은 회사원이에요.
I used to be a student, and now I'm an office worker.
Common mistakes & nuance
Both clauses normally need their own past marker; adding 고 to only the second verb (e.g. '이기고 KT가 졌습니다') leaves the first action's timing unclear. 였고 is used only after 하다-type stems (했고), not as a general past-tense option.
Similar grammar
- -고
-고 simply connects two clauses without marking tense on the first one; tense is usually shown only at the very end. -았/었/였고 repeats the past marker on each clause, which is common when narrating a sequence of completed past events.
- -아서/어서
-아서/어서 links two clauses with a cause-and-result or sequential meaning ('because', 'and so'), and cannot take a past-tense marker before it. -았/었/였고 has no cause meaning — it simply lists past facts side by side.