Past Tense -았/었-: Meaning, Rules and Examples

What you'll learn

• Choose 았, 었 or 했 by the last vowel of the stem.
• Merge vowel-final stems correctly, as in 가+았 to 갔 and 보+았 to 봤.
• Attach the same infix to polite, formal, casual and plain endings.
• Tell -았/었- from -았었- and -고 있었다.

Before you start: you should know the polite ending -아요/어요 and the verb-last sentence pattern. Time: about 30 minutes.

What Does the past Tense -았/었- Mean?

The past tense -았/었- marks an action or state that is finished at the moment of speaking. It is an infix (선어말어미), a small piece placed inside a word between the stem and the final ending. The stem carries the meaning, the infix carries the tense, and the ending carries the politeness.

Compare the present with the past:

The only difference is the infix 었 inserted before 어요. Korean past forms cover both the English simple past ("I ate") and the present perfect ("I have eaten"), so 점심 먹었어요? can mean "Did you eat lunch?" or "Have you had lunch?"

A First Example

Listen to each sentence at normal speed, then slowly.

1. 어제 영화를 봤어요. (eoje yeonghwareul bwasseoyo) "I watched a movie yesterday."

Pronunciation: [어제 영화를 봐써요]. The stem 보 plus the infix 았 merges into 봤, and the double ㅆ is spoken as a doubled s sound.

2. 밥을 먹었어요. (babeul meogeosseoyo) "I ate a meal."

Pronunciation: [바블 머거써요]. The final ㅂ of 밥 moves onto the next syllable, and the final ㄱ of 먹 moves onto 었.

One sentence merges the stem with the infix, and the other keeps them apart. The next section explains when each happens.

How Does the past Tense -았/었- Work?

The infix is chosen by the last vowel of the stem, using the same vowel harmony as the polite ending. 았 follows ㅏ or ㅗ, 었 follows every other vowel, and 하다 verbs use 했. After the infix, any ending can follow.

Pattern Table

Three details make the table easy to apply.

1. Look at the last vowel of the stem only. 먹 ends in ㅓ, so the infix is 었. The same logic gives 좋았 for 좋, with ㅗ.
2. Spell the infix with ㅆ. The double consonant is part of the infix: 았, 었, 했. A single ㅅ, as in 갓어요, is a spelling error.
3. Use 했 for every 하다 verb. 했 is the contracted form of 하였. The long form 하였- survives in formal writing (공부하였다), but 하었어요 and 하았어요 are never used.

Vowel-Final Stems Merge with the Infix

When a stem ends in a vowel, the stem vowel and the infix merge into one syllable that carries the ㅆ.

The pattern is the same as in the polite present: ㅏ plus 았 keeps one ㅏ, ㅗ plus 았 becomes ㅘ, ㅜ plus 었 becomes ㅝ, and ㅣ plus 었 becomes ㅕ. The only new detail is the ㅆ at the bottom of the merged syllable.

Adjectives and Irregular Stems

Adjectives (descriptive verbs) take the same infix. A few stems also change before the infix, so the irregular change comes first and the vowel rule second.

The full set of irregular classes is in how to conjugate Korean verbs in past tense. Use the Korean verb conjugator when you are unsure.

One Infix, Every Ending

The infix stays the same at every speech level and in every connecting ending. Only the part after it changes.

This regularity is why the infix is worth learning once. The next section builds a sentence step by step.

How Do You Make a past Tense Sentence with -았/었-?

To make a past sentence, take the dictionary form, remove 다, check the last vowel, add 았, 었 or 했, merge if needed, then add the ending. Follow these steps with 어제 영화를 봤어요.

1. Start from the dictionary form. 보다 ("to see").
2. Remove 다. The stem is 보.
3. Check the last vowel. 보 ends in ㅗ, so the infix is 았.
4. Merge the stem and the infix. 보 + 았 becomes 봤.
5. Add the ending. For the polite style, add 어요: 봤어요.
6. Add the other words. 어제 영화를: 어제 영화를 봤어요.

You'll know it worked when the verb ends in 요 and has the double ㅆ in the middle. Common mistake at this step: adding the infix to the whole word without removing 다, as in 보다았어요. Remove 다 first.

Repeat the steps with two more verbs. For 먹다, the stem is 먹, the last vowel is ㅓ, and the polite past is 먹었어요. For 공부하다, the stem is 공부하, the verb ends in 하, and the polite past is 공부했어요.

With the sentence built, the next section compares the plain past with two similar forms.

How Is -았/었- Different from -았었- and -고 있었다?

-았/었- reports a finished event, -았었- reports a past felt as cut off from now, and -고 있었다 reports an action in progress at a past time. All three are past, but they describe different shapes of the event.

Pronunciation: 살았었어요 is [사라써써요] (sarasseosseoyo), 살고 있었어요 is [살고 이써써요] (salgo isseosseoyo), and 세 시에 공부하고 있었어요 is [세 시에 공부하고 이써써요]. The plain -았/었- suits most past sentences, so beginners should use it first. The other two are taught in Korean aspect and Korean progressive tense. The wider set is in Korean past tense. The next section covers where the past form carries a present meaning.

When Does a past Form Mean Something in the Present?

Some Korean past forms describe a state that is true now. The action finished, and its result remains. This is a rare feature that surprises learners, because the English translation uses the present tense.

Pronunciation: 알았어요 is [아라써요] (arasseoyo), 다 왔어요 is [다 와써요] (da wasseoyo), 결혼했어요 is [결혼해써요] (gyeolhonhaesseoyo), 늦었어요 is [느저써요] (neujeosseoyo), and 잘 먹었습니다 is [잘 머걷씀니다] (jal meogeotseumnida). The last phrase is said after a meal, so the finished action is the point. Questions and negatives use the same infix: 먹었어요? ("Did you eat?") and 안 먹었어요 ("I did not eat"), pronounced [안 머거써요]. See negative past tense in Korean for the negative forms.

Limitation: this lesson covers the regular and common irregular forms of -았/었-. It does not cover the past of 이다, which is taught in 이었어요/였어요 past of 이다, or the plain past in diaries and news, which is taught in plain past -았다/었다. The next section lists the errors to avoid.

What Mistakes Do Learners Make?

Six mistakes cover most wrong past forms.

1. Using 았 after a stem with ㅓ. Learners match 았 with every verb that sounds "short". Actually only ㅏ and ㅗ take 았. 먹았어요 is wrong, and 먹었어요 is right.
2. Writing a single ㅅ. 갓어요 is wrong. The infix has a double ㅆ: 갔어요.
3. Keeping the present form with a past time word. 어제 가요 mixes "yesterday" with a present ending. Say 어제 갔어요.
4. Marking the past twice. 갔었어요 is a different form, for a past cut off from now. For an ordinary past, say 갔어요.
5. Adding 어 to 하다. 공부하었어요 is wrong. Every 하다 verb takes 했: 공부했어요.
6. Leaving an irregular stem unchanged. 듣었어요 is wrong, because 듣 changes to 들. Say 들었어요.

The same habits carry over to korean present tense uses, and the sentence pattern behind every example is explained in the Korean SOV sentence pattern. Now test yourself.

Practice and Answers

Try all four items before you read the answers. Each answer has audio, normal and slow.

1. Choose the form. 읽다 ("to read"): 읽았어요 or 읽었어요?
2. Fix the error. 어제 학교에 가요. (The speaker wants to say "I went to school yesterday.")
3. Translate. "I studied Korean yesterday."
4. Write your own. Write one past sentence about what you did this morning, using 마시다 (to drink) or 먹다 (to eat).

Answer Key

1. 읽었어요 (ilgeosseoyo) Pronounced [일거써요]. The last vowel of 읽 is ㅣ, so the infix is 었.

2. 어제 학교에 갔어요. (eoje hakgyoe gasseoyo) Pronounced [어제 학꾜에 가써요]. The time word 어제 needs a past ending.

3. 어제 한국어를 공부했어요. (eoje hangugeoreul gongbuhaesseoyo) Pronounced [어제 한구거를 공부해써요]. Every 하다 verb takes 했.

4. Sample answer: 아침에 커피를 마셨어요. (achime keopireul masyeosseoyo) "I drank coffee in the morning." Pronounced [아치메 커피를 마셔써요]. Any morning action with a correct 았/었 infix is right.

If you chose the wrong infix, check the last vowel of the stem: ㅏ or ㅗ takes 았, other vowels take 었, and 하다 takes 했. Then continue with the next lessons.

What Should You Learn Next?

After the past tense -았/었-, the natural next lesson is 이었어요/였어요 past of 이다, which adds "was" and "were" after a noun. For the written style, study plain past -았다/었다. To see the neighbouring tense that stresses a past that no longer holds, read past perfect -았었-. The set overview, Korean past tense, lists every lesson in order.

This page uses Revised Romanization only as a learning aid; the Hangul is the reference. To remember the idea in one line: the past tense -았/었- adds 았 after ㅏ or ㅗ, 었 after other vowels and 했 to 하다 verbs, between the stem and any ending.

Frequently Asked Questions

What Does -았/었- Mean in Korean?

-았/었- is the past tense infix. It marks a finished action or a past state and sits between the verb stem and the final ending, as in 먹었어요 (I ate). Korean past forms cover both the English simple past and the present perfect, so 점심 먹었어요? can mean "Did you eat lunch?" or "Have you eaten lunch?".

How Do I Choose between 았 and 었?

Look at the last vowel of the stem. Use 았 after ㅏ or ㅗ, as in 좋았어요 and 살았어요, and 었 after any other vowel, as in 먹었어요 and 읽었어요. For 하다 verbs use 했, as in 공부했어요. The vowels before the last vowel of the stem do not matter.

What Is the Most Common Mistake with -았/었-?

The most common mistake is using 았 after a stem whose last vowel is ㅓ: 먹았어요 is wrong, and 먹었어요 is right. Check the last vowel only. A second mistake is keeping the present form with a past time word, as in 어제 가요, which should be 어제 갔어요.

How Is -았/었- Different from -았었-?

-았/었- reports a finished event, and -았었- reports a past felt as cut off from now. 살았어요 means "I lived there", while 살았었어요 means "I used to live there, but not anymore". Beginners should use -았/었- for most past sentences and learn -았었- later in the aspect lessons.

Do I Use -았/었- in Speech, Writing or Both?

Both. -았/었- appears in speech and writing with the same spelling. The ending after it changes by style: 먹었어요 in polite speech, 먹었습니다 in formal speech, 먹었어 in casual speech and 먹었다 in plain writing. Only the final ending changes; the infix stays the same.

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