Past Tense -았/었 in Korean

Overview

The past tense in Korean is formed by adding -았/었 to the verb stem, following the same vowel harmony rules as the polite ending. This CEFR A1 concept allows you to talk about completed actions and past states. The past tense marker is inserted between the stem and the speech level ending, so you get forms like -았어요 (polite past) or -았습니다 (formal past).

Korean past tense is simpler than many European languages because there is only one past form — no distinction between simple past, imperfect, or past perfect at the basic level. The single past marker covers "I went," "I was going," and "I had gone" in most everyday contexts.

The 하다 → 했 contraction is extremely common and should be memorized early, as 하다 verbs make up a large portion of Korean vocabulary.

How It Works

Formation

Stem ending	Past marker	Example
ㅏ or ㅗ vowel	-았-	가- → 갔- (went)
Other vowels	-었-	먹- → 먹었- (ate)
하-	-였- → 했-	하- → 했- (did)

Then add speech level ending:

Past stem	+ Polite	+ Formal
갔-	갔어요	갔습니다
먹었-	먹었어요	먹었습니다
했-	했어요	했습니다

Common Past Tense Forms

Dictionary	Past polite	Romanization	English
가다	갔어요	ga-sseo-yo	went
먹다	먹었어요	meo-geo-sseo-yo	ate
하다	했어요	hae-sseo-yo	did
오다	왔어요	wa-sseo-yo	came
마시다	마셨어요	ma-syeo-sseo-yo	drank
보다	봤어요	bwa-sseo-yo	saw
있다	있었어요	i-sseo-sseo-yo	was/had
좋다	좋았어요	jo-a-sseo-yo	was good

Examples in Context

Korean	Romanization	English	Note
갔어요	ga-sseo-yo	went	ㅏ stem → 았
먹었어요	meo-geo-sseo-yo	ate	consonant stem → 었
했어요	hae-sseo-yo	did	하 → 했
재미있었어요	jae-mi-i-sseo-sseo-yo	was fun	descriptive past
어제 뭐 했어요?	eo-je mwo hae-sseo-yo	What did you do yesterday?	question
한국에 갔어요.	han-gu-ge ga-sseo-yo	(I) went to Korea.	past destination
많이 먹었어요.	ma-ni meo-geo-sseo-yo	(I) ate a lot.	past with adverb
작년에 결혼했어요.	jang-nyeo-ne gyeol-hon-hae-sseo-yo	(I) got married last year.	하다 verb past
날씨가 추웠어요.	nal-ssi-ga chu-wo-sseo-yo	The weather was cold.	irregular past
재미없었어요.	jae-mi-eop-seo-sseo-yo	It wasn't fun.	negative past

Common Mistakes

Applying the wrong vowel harmony in past tense

• Wrong: 먹 + 았어요 → 먹았어요
• Right: 먹 + 었어요 → 먹었어요
• Why: The last vowel in 먹 is ㅓ (not ㅏ/ㅗ), so it takes -었.

Double-marking tense in connected clauses

• Wrong: 먹었고 갔었어요 (past in both clauses)
• Right: 먹고 갔어요 (past only on final verb)
• Why: When clauses are connected with -고, only the final verb typically carries the tense marker.

Confusing past tense with past experience

• Wrong: Using -았/었어요 when meaning "have you ever..."
• Right: Use -아/어 봤어요 for experience: 한국에 가 봤어요? (Have you been to Korea?)
• Why: Simple past describes specific past events; the experience pattern (-아/어 보다) asks about life experience.

Usage Notes

Korean past tense covers a broad range of English tenses. Context and time expressions (어제, 지난주, 작년) clarify exactly when something happened. In narratives, the past tense is used consistently for events in sequence. The past tense can also express a completed realization: 알았어요 can mean "I understood" or "I got it."

Practice Tips

• Write a short diary entry in Korean each evening using past tense. Describe what you did: 아침을 먹었어요. 학교에 갔어요. 공부했어요.
• Practice converting present polite forms to past: 가요 → 갔어요, 먹어요 → 먹었어요. Do this with 20 common verbs.
• When watching Korean content, listen for the -었/았 sound before -어요 or -습니다 to recognize past tense in real speech.

Related Concepts

• Prerequisite: Polite Ending -아/어요 — past tense builds on the polite conjugation pattern
• Next steps: Retrospective -더- — a nuanced past tense for recalling personal observations