Korean Past Tense Guide: 았어요, 었어요, 했어요, and Real Usage

Korean past tense is formed by attaching a past marker to a verb or descriptive-verb stem, then adding the appropriate speech-level ending. In everyday polite Korean, the three forms you need first are 았어요 /a.s͈ʌ.jo/, 었어요 /ʌ.s͈ʌ.jo/, and 했어요 /hɛ.s͈ʌ.jo/. Once you can choose between them, you can say you ate, went, saw, studied, liked, and were tired in natural Korean.

Korean is spoken across the Korean Peninsula and by diaspora communities worldwide. The two countries where it is the main national language, South Korea and North Korea, have a combined population of roughly 78 million people according to United Nations population estimates. Past tense is therefore not just a textbook pattern: it is one of the most frequent structures you will hear in Korean dramas, variety shows, daily chats, and workplace conversations.

Before learning irregular forms, make sure you know the basic dictionary form. Korean verbs end in 다 /ta/ in dictionaries, such as 먹다 /mʌk.t͈a/, to eat, and 가다 /ka.da/, to go. For a wider overview of verb endings and speech levels, see our Korean verb conjugation guide.

The core Korean past tense pattern

The polite everyday past tense ends in 요 /jo/. It is appropriate with shop staff, teachers, colleagues, new acquaintances, and anyone you should address respectfully.

The basic formula is:

The vowel in the verb stem usually determines whether you choose 았어요 /a.s͈ʌ.jo/ or 었어요 /ʌ.s͈ʌ.jo/. The result may contract, which is why the final form sometimes looks shorter than the original stem plus ending.

Korean grammar specialists Jaehoon Yeon and Lucien Brown describe tense as part of a larger system that also communicates politeness, aspect, and speaker attitude. That is useful to remember: a past ending tells you about time, but the ending after it tells you how the speaker positions themselves socially.

When to use 았어요

Use 았어요 /a.s͈ʌ.jo/ when the final vowel of the stem is 아 /a/ or 오 /o/. In normal speech, the vowels often merge into a shorter form.

Notice these frequent contractions:

• 가았어요 becomes 갔어요 /ka.s͈ʌ.jo/
• 보았어요 becomes 봤어요 /pwa.s͈ʌ.jo/
• 오았어요 becomes 왔어요 /wa.s͈ʌ.jo/

You do not need to pronounce the uncontracted versions. Learn the natural forms as complete units.

Past-tense examples with 았어요

어제 학교에 갔어요. /ʌ.dʑe hak.k͈jo.e ka.s͈ʌ.jo/ means “I went to school yesterday.”

영화를 봤어요. /jʌŋ.hwa.rɯl pwa.s͈ʌ.jo/ means “I watched a movie.”

친구가 왔어요. /tɕʰin.gu.ɡa wa.s͈ʌ.jo/ means “A friend came.”

The subject is often omitted when context makes it obvious. Korean speakers commonly say 갔어요 /ka.s͈ʌ.jo/ alone when everyone already knows who went somewhere.

When to use 었어요

Use 었어요 /ʌ.s͈ʌ.jo/ after most stem vowels other than 아 /a/ and 오 /o/. This is the most common past-tense ending you will meet.

The spelling may change as vowels combine. For example, 마시었어요 contracts to 마셨어요 /ma.ɕjʌ.s͈ʌ.jo/. Likewise, 주었어요 contracts to 줬어요 /tɕwʌ.s͈ʌ.jo/.

Past-tense examples with 었어요

김밥을 먹었어요. /kim.p͈a.bɯl mʌ.ɡʌ.s͈ʌ.jo/ means “I ate kimbap.”

한국어를 배웠어요. /han.gu.ɡʌ.rɯl pɛ.wʌ.s͈ʌ.jo/ means “I learned Korean.”

책을 읽었어요. /tɕʰɛ.gɯl il.ɡʌ.s͈ʌ.jo/ means “I read a book.”

The National Institute of Korean Language treats these forms as standard conjugational patterns, but speaking practice matters because contractions are heard far more often than learners expect. Listening to short scenes and repeating whole lines makes forms such as 봤어요 /pwa.s͈ʌ.jo/ and 배웠어요 /pɛ.wʌ.s͈ʌ.jo/ much easier to retrieve.

하다 verbs and 했어요

Verbs ending in 하다 /ha.da/ are especially useful because Korean creates many actions by joining a noun to 하다 /ha.da/, to do. Their past form is 했어요 /hɛ.s͈ʌ.jo/.

어제 공부했어요. /ʌ.dʑe koŋ.bu.hɛ.s͈ʌ.jo/ means “I studied yesterday.”

주말에 운동했어요. /tɕu.ma.re un.doŋ.hɛ.s͈ʌ.jo/ means “I exercised over the weekend.”

Because so many Korean words use 하다 /ha.da/, this one pattern gives you immediate access to hundreds of useful past-tense sentences.

Past tense with descriptive verbs

English separates verbs from adjectives, but Korean words describing states and qualities behave grammatically like verbs. You conjugate them for tense in the same way.

영화가 재미있었어요. /jʌŋ.hwa.ɡa tɕɛ.mi.i.s͈ʌ.s͈ʌ.jo/ means “The movie was fun.”

어제 너무 바빴어요. /ʌ.dʑe nʌ.mu pa.p͈a.s͈ʌ.jo/ means “I was very busy yesterday.”

This pattern is essential for talking about impressions after a trip, meal, date, class, or show. If you want to talk about liking someone, compare the past form 좋아했어요 /tɕo.a.hɛ.s͈ʌ.jo/, liked, with the present expression in our guide to saying I love you in Korean.

Negatives in the Korean past tense

There are two high-frequency ways to say that something did not happen.

The first is 안 /an/ before the verb:

The second uses 못 /mot/, which means someone could not do an action, often because of circumstance or ability:

어제 못 갔어요. /ʌ.dʑe mot ka.s͈ʌ.jo/ means “I could not go yesterday.”

숙제를 못 했어요. /suk.tɕe.rɯl mot hɛ.s͈ʌ.jo/ means “I could not do my homework.”

Do not treat 안 /an/ and 못 /mot/ as identical. 안 갔어요 /an ka.s͈ʌ.jo/ can suggest a choice not to go. 못 갔어요 /mot ka.s͈ʌ.jo/ suggests that something prevented the trip.

A fuller negative form is 하지 않았어요 /ha.dʑi a.na.s͈ʌ.jo/, did not do. It is grammatically correct but often sounds more formal or emphatic than 안 했어요 /an hɛ.s͈ʌ.jo/ in everyday conversation.

Key irregular past-tense verbs

Korean past tense has several irregular patterns. The good news is that they are predictable once you identify the verb type. Ho-min Sohn’s Korean Language emphasizes the importance of learning stems alongside their common inflected forms, rather than memorizing dictionary forms in isolation.

ㄷ irregular verbs

Some verbs ending in ㄷ /t/ change it to ㄹ /l/ before a vowel-ending suffix.

But not every ㄷ /t/ verb changes. 받다 /pat.t͈a/, to receive, becomes 받았어요 /pa.da.s͈ʌ.jo/, not a form with ㄹ /l/.

ㅂ irregular descriptive verbs

Many descriptive verbs ending in ㅂ /p/ change to a sound like 우 /u/ before the past ending.

A major exception is 돕다 /top.t͈a/, to help, which becomes 도왔어요 /to.wa.s͈ʌ.jo/.

르 irregular verbs

Verbs such as 모르다 /mo.rɯ.da/, not to know, gain an extra ㄹ /l/ before the past ending.

몰랐어요 /mol.ra.s͈ʌ.jo/ means “did not know.”

부르다 /pu.rɯ.da/, to call or sing, becomes 불렀어요 /pul.lʌ.s͈ʌ.jo/.

으 drop verbs

For many verbs with 으 /ɯ/ in the final syllable, 으 /ɯ/ disappears before the ending.

쓰다 /s͈ɯ.da/, to write or use, becomes 썼어요 /s͈ʌ.s͈ʌ.jo/.

크다 /kʰɯ.da/, to be big, becomes 컸어요 /kʰʌ.s͈ʌ.jo/.

Casual speech: 았어, 었어, 했어

With friends, siblings, close partners, and people who use casual speech with you, remove 요 /jo/:

어제 뭐 했어? /ʌ.dʑe mwʌ hɛ.s͈ʌ/ means “What did you do yesterday?”

집에 갔어. /tɕi.be ka.s͈ʌ/ means “I went home.”

Speech level matters as much as tense. A friendly 안녕 /an.njʌŋ/ may work between close peers, but switching to casual past endings too quickly can sound presumptuous. Review how to say hello in Korean and how to say goodbye in Korean to see how relationship and setting shape natural Korean.

A practical way to learn past tense faster

Memorize verbs as paired forms, not as isolated dictionary entries. Learn 먹다 /mʌk.t͈a/ → 먹었어요 /mʌ.ɡʌ.s͈ʌ.jo/, 가다 /ka.da/ → 갔어요 /ka.s͈ʌ.jo/, and 하다 /ha.da/ → 했어요 /hɛ.s͈ʌ.jo/ together.

Then practice short, personally true sentences:

• 어제 한국어를 공부했어요. /ʌ.dʑe han.gu.ɡʌ.rɯl koŋ.bu.hɛ.s͈ʌ.jo/, “I studied Korean yesterday.”
• 저녁에 밥을 먹었어요. /tɕʌ.njʌ.ɡe pa.bɯl mʌ.ɡʌ.s͈ʌ.jo/, “I ate a meal in the evening.”
• 친구를 만났어요. /tɕʰin.gu.rɯl man.na.s͈ʌ.jo/, “I met a friend.”
• 드라마를 봤어요. /tɯ.ra.ma.rɯl pwa.s͈ʌ.jo/, “I watched a drama.”

Past-tense dialogue is especially common in entertainment because characters constantly explain what happened, ask where someone went, or react to a completed event. When you hear a useful line in a Korean show, pause and identify the stem, the past marker, and the politeness level. That turns passive viewing into grammar practice.

The essential rule to remember

For everyday Korean past tense, use 았어요 /a.s͈ʌ.jo/ after 아 /a/ or 오 /o/ vowels, 었어요 /ʌ.s͈ʌ.jo/ after most other vowels, and 했어요 /hɛ.s͈ʌ.jo/ for 하다 /ha.da/ verbs. Learn common contractions and irregular verbs as whole forms, and choose 요 /jo/ or no 요 /jo/ according to your relationship with the listener.

Once these three patterns become automatic, you can tell stories, describe yesterday, discuss movies, and understand a large share of basic Korean conversation.