Korean Past Tense Conjugation: How to Choose Between 았어요, 었어요, and 했어요

When learners first encounter Korean past tense, forms like 았어요, 었어요, and 했어요 can seem like completely different grammar patterns.

In reality, they all express the same basic past tense meaning. The difference comes from Korean conjugation rules and the final vowel of the verb stem.

This guide explains how Korean past tense conjugation works, how to choose the correct ending, and why native speakers rarely think about these forms as separate grammar structures.

1. What Are 았어요, 었어요, and 했어요 in Korean?

Learn how 았어요, 었어요, and 했어요 work as the most common Korean past tense endings in everyday informal polite speech.

Korean uses -았어요, -었어요, and -했어요 to talk about actions, experiences, and situations that already happened.

Although these endings look different, they all express the same basic past tense meaning. The difference comes from how Korean verbs are conjugated.

Examples

• 어제 창문을 열었어요.
(I opened the window yesterday.)

• 지난주에 선물을 받았어요.
(I received a gift last week.)

• 주말에 요리했어요.
(I cooked during the weekend.)

The sections below explain how Korean speakers choose the correct ending.

2. How to Choose Between 았어요 and 었어요

Learn the simple Korean past tense rule that determines when to use 았어요 and when to use 었어요.

How to Choose the Correct Korean Past Tense Ending

If the Verb Stem Ends With	Use
ㅏ or ㅗ	-았어요
Most Other Vowels	-었어요
하다	-했어요

The choice is based on the final vowel of the verb stem, not the meaning of the sentence.

Step 1: Find the Verb Stem

Korean past tense endings attach to the verb stem rather than the dictionary form.

Examples

• 가다 → 가
(to go → stem: 가)

• 먹다 → 먹
(to eat → stem: 먹)

• 하다 → 하
(to do → stem: 하)

The final vowel of the stem determines which past tense ending to use.

Step 2: Check the Final Vowel

If the final vowel of the verb stem is ㅏ or ㅗ, use -았어요.

For most other vowels, use -었어요.

하다 verbs follow their own pattern and become 했어요.

Use -았어요 After ㅏ or ㅗ

When the final vowel of the verb stem is ㅏ or ㅗ, Korean normally uses -았어요.

Examples

• 문을 닫았어요.
(I closed the door.)

• 손을 잡았어요.
(I held someone’s hand.)

• 빵을 팔았어요.
(I sold bread.)

Use -었어요 With Most Other Vowels

If the final vowel is not ㅏ or ㅗ, Korean usually uses -었어요.

Examples

• 얼굴을 씻었어요.
(I washed my face.)

• 친구에게 편지를 보냈어요.
(I sent a letter to a friend.)

• 도서관에서 책을 빌렸어요.
(I borrowed a book from the library.)

Common Contractions in Korean Past Tense

Some verbs become shorter when they combine with a past tense ending.

Examples

• 오르다 → 올랐어요
  (to go up → went up)
• 배우다 → 배웠어요
  (to learn → learned)
• 세우다 → 세웠어요
  (to set up → set up)
• 모으다 → 모았어요
  (to collect → collected)

These are not different grammar patterns. They are simply the natural contracted forms used in everyday Korean.

A Quick Note About Irregular Verbs

Some Korean verbs change differently when they combine with past tense endings. However, most beginner-level verbs follow the regular patterns introduced in this guide. Once these patterns feel familiar, irregular verb conjugation becomes much easier to learn.

3. Why 하다 Verbs Become 했어요

Discover why Korean 하다 verbs change to 했어요 and how this pattern works in everyday conversation.

하다 verbs follow their own past tense pattern.

Instead of becoming 하았어요 or 하었어요, they become 했어요.

This pattern appears in everyday verbs that people use at school, at work, while traveling, and in daily life.

Examples

• 예약했어요.
(I made a reservation.)

• 설명했어요.
(I explained it.)

• 사용했어요.
(I used it.)

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The same pattern applies to many other 하다 verbs.

More Examples

• 출발했어요.
(I departed.)

• 시작했어요.
(I started.)

• 준비했어요.
(I prepared it.)

하다 verbs are everywhere in Korean, which is why 했어요 appears so often in real conversations.

Learn More

Want to see how 하다 verbs work in the present tense before changing to 했어요?

👉 Korean Present Tense: How to Use -아요/-어요/-해요

4. Korean Past Tense Conjugation Chart

Use this Korean past tense conjugation chart to quickly identify the correct ending for common verbs.

Korean Past Tense Conjugation Chart

Korean Verb	Korean Past Tense
고르다 (to choose)	골랐어요 (chose)
크다 (to be big)	컸어요 (was big)
돌리다 (to turn)	돌렸어요 (turned)
심다 (to plant)	심었어요 (planted)
확인하다 (to check)	확인했어요 (checked)
신청하다 (to apply)	신청했어요 (applied)

This chart is useful for spotting common past tense patterns, but the final vowel of the verb stem is still the quickest way to choose the correct ending.

Native Speaker Shortcut

Native Korean speakers rarely stop to think about whether a verb should use -았어요 or -었어요. Instead, they recognize familiar verb patterns they have heard and used many times before.

5. Common Learner Misunderstandings About Korean Past Tense

These common misunderstandings explain why Korean past tense endings often seem more complicated than they really are.

Misunderstanding 1: 았어요 and 었어요 Have Different Meanings

았어요 and 었어요 are sometimes treated as two different kinds of past tense.

They are not.

Both endings describe actions or situations that already happened.

The choice depends on the verb stem, not the meaning.

Examples

• 어제 꽃을 샀어요.
(I bought flowers yesterday.)

• 저녁에 뉴스를 들었어요.
(I listened to the news in the evening.)

Both sentences describe past actions even though they use different endings.

Misunderstanding 2: Contracted Forms Are Exceptions

At first glance, contracted forms can look unrelated to their dictionary forms.

They are not exceptions.

They follow regular contraction patterns that appear throughout Korean conjugation.

Examples

• 오다 → 왔어요

(to come → came)

• 크다 → 컸어요

(to be big → was big)

The spelling changes, but the underlying pattern remains consistent.

Misunderstanding 3: 했어요 Is a Separate Grammar Pattern

Because 했어요 appears so frequently, it is easy to treat it as a grammar pattern of its own.

In reality, it is simply the past tense form of 하다 verbs.

Examples

• 숙제했어요.
(I did my homework.)

• 연습했어요.
(I practiced.)

• 소개했어요.
(I introduced myself.)

하다 verbs always become 했어요 in the past tense.

6. How Native Koreans Use Past Tense in Everyday Conversations

See how Korean past tense endings appear naturally in real conversations about past actions and experiences.

Conversation 1

• A: 어제 어디에 갔어요?
(Where did you go yesterday?)

• B: 병원에 갔어요.
(I went to the hospital.)

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Conversation 2

• A: 주말에 뭐 했어요?
(What did you do during the weekend?)

• B: 가족을 만났어요.
(I met my family.)

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Conversation 3

• A: 점심에 뭐 먹었어요?
(What did you eat for lunch?)

• B: 김밥을 먹었어요.
(I ate gimbap.)

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Conversation 4

• A: 어제 뭐 봤어요?
(What did you watch yesterday?)

• B: 다큐멘터리를 봤어요.
(I watched a documentary.)

What You Will Hear Most Often

Questions such as “어디에 갔어요?”, “뭐 했어요?”, and “뭐 먹었어요?” are among the most common Korean past tense patterns in everyday conversation. Native speakers use these questions frequently when talking about recent experiences, daily routines, and past events.

Learn More

Now that you can talk about past events, learn how to talk about future plans in Korean.

👉 Korean Future Expression: -(으)ㄹ 거예요

7. Quick Practice: Korean Past Tense Conjugation

Test your understanding of Korean past tense conjugation by choosing the correct form for each verb.

Practice Questions

#	Korean Sentence	English Translation
1	어제 컴퓨터를 (고치다) → ______	I repaired my computer yesterday.
2	친구를 집에 (초대하다) → ______	I invited a friend to my house.
3	가방을 의자 위에 (놓다) → ______	I put my bag on the chair.
4	주말에 케이크를 (만들다) → ______	I made a cake during the weekend.
5	방을 깨끗하게 (정리하다) → ______	I cleaned and organized my room.
6	영화가 슬퍼서 (울다) → ______	I cried because the movie was sad.
7	밤에 불을 (켜다) → ______	I turned on the light at night.
8	공항에서 비행기를 (타다) → ______	I boarded a plane at the airport.
9	선생님께 (인사하다) → ______	I greeted my teacher.
10	주말에 공원을 (방문하다) → ______	I visited a park during the weekend.

Answers and Explanations

1. 고치다 → 고쳤어요 — 고치다 does not end in ㅏ or ㅗ, so it follows the -었어요 pattern.

2. 초대하다 → 초대했어요 — 하다 verbs become 했어요 in the past tense.

3. 놓다 → 놓았어요 — 놓다 ends with ㅗ, so it uses -았어요.

4. 만들다 → 만들었어요 — 만들다 follows the -었어요 pattern.

5. 정리하다 → 정리했어요 — The same pattern applies to many common action verbs ending in 하다.

6. 울다 → 울었어요 — 울다 follows the standard -었어요 pattern.

7. 켜다 → 켰어요 — 켜다 combines with -었어요 and contracts to 켰어요.

8. 타다 → 탔어요 — 타다 ends with ㅏ, so it uses -았어요 and contracts to 탔어요.

9. 인사하다 → 인사했어요 — This is another everyday example of the 하다 → 했어요 change.

10. 방문하다 → 방문했어요 — The past tense form follows the same conjugation pattern used by other 하다 verbs.

8. Frequently Asked Questions About Korean Past Tense

These frequently asked questions answer common questions about Korean past tense endings and conjugation rules.

Q1. What is the Korean past tense?

The Korean past tense is used to describe actions, experiences, or situations that already happened. In everyday polite speech, it is most commonly expressed with endings such as -았어요, -었어요, and -했어요.

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Q2. How do I know whether to use 았어요 or 었어요?

The choice depends on the final vowel of the verb stem. Verbs ending in ㅏ or ㅗ usually take -았어요, while most other verbs take -었어요. This rule applies to most regular Korean verbs.

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Q3. Is 았어요/었어요 formal or casual?

았어요 and 었어요 belong to the informal polite speech level known as 해요체. They are commonly used in daily conversations and are less formal than styles such as -습니다.

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Q4. Can Korean adjectives use past tense endings?

Yes. Korean adjectives use the same past tense endings as verbs, including -았어요 and -었어요, to describe past states, feelings, or conditions.

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Q5. Are there irregular verbs in Korean past tense conjugation?

Yes. Some Korean verbs follow irregular conjugation patterns when forming the past tense. However, most beginner-level verbs follow regular patterns before learners study irregular verb groups in more detail.

9. Conclusion: Using Korean Past Tense More Naturally

Korean past tense endings may look different at first, but they follow clear patterns. In most cases, the final vowel of the verb stem tells you whether to use -았어요 or -었어요, while 하다 verbs become 했어요.

Rather than memorizing every form individually, focus on recognizing these patterns. With regular exposure, forms like 갔어요, 먹었어요, and 했어요 become much easier to recognize and use in everyday Korean conversations.

10. Related Korean Grammar Guides

Continue building your Korean conversation skills with these related grammar guides.

Essential Grammar

👉 Korean Informal Polite Speech Explained: Present, Past, Future, and Questions

👉 Korean Present Tense: How to Use -아요/-어요/-해요

👉 Korean Future Expression: -(으)ㄹ 거예요

Korean Verb Conjugation

👉 Korean Irregular Verb Conjugation Guide