Korean Past Tense: -았/-었 Explained
10-Second Answer
-았/-었 marks past tense, inserted right before the polite ending -어요 becomes -었어요. It follows the exact same bright/dark vowel rule as present tense: ㅏ/ㅗ stems take -았, everything else takes -었.
The Pattern: Present → Past
| Verb | Present (-아/어요) | Past (-았/었어요) |
|---|---|---|
| 가다 (go) | 가요 | 갔어요 |
| 먹다 (eat) | 먹어요 | 먹었어요 |
| 하다 (do) | 해요 | 했어요 |
| 오다 (come) | 와요 | 왔어요 |
If you already know a verb's present tense, past tense is nearly automatic: swap 요 for 어요, using the same vowel that's already there.
Quick Examples
어제 학교에 갔어요.
eoje hakgyo-e gasseoyo.
I went to school yesterday.
밥 먹었어요?
bap meogeosseoyo?
Did you eat?
The greeting from earlier — now you see its grammar.
재미있었어요.
jaemiisseosseoyo.
It was fun.
Formal and Casual Past Tense
| Level | Form | Example |
|---|---|---|
| Formal | -았/었습니다 | 갔습니다 (went) |
| Polite | -았/었어요 | 갔어요 (went) |
| Casual | -았/었어 | 갔어 (went) |
One Irregular Worth Memorizing: 이다 (to be)
이에요/예요 ("to be," polite) becomes 이었어요/였어요 in the past — not a simple -았/었 swap, so it's worth memorizing directly:
학생이었어요.
I was a student.
학생(consonant-ending) + 이었어요.
친구였어요.
It was a friend.
친구(vowel-ending) + 였어요.
Common Mistakes
Mistake #1 — Applying -았/었 directly to 이다
이다's past tense isn't 이아써요 — it's 이었어요/였어요, following its own vowel-contraction pattern.
Mistake #2 — Forgetting 하다 stays irregular in the past too
했어요, not 하았어요 — consistent with 해요 in the present.
Mini Quiz
1. 받다 (to receive) is 받아요 in the present. What's the past tense?
2. How do you say "I was a student"?
3. What's the past tense of 하다 (해요 in present)?
Related Knowledge
Learn Next
What Does -고 싶다 Mean? Saying 'I Want To' in Korean
Present and past done — now add the ending that lets you say what you WANT to do.
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Start today's study →Last updated: 2026-08-10 · Written and reviewed by a native Korean speaker.