-았/었- as Both Past and Present Perfect

English forces you to choose between "I ate" and "I have eaten," and it builds the second one with a whole extra verb, have. Korean does neither. The single marker -았/었- covers both meanings, and there is no "have" to add anywhere. This is genuinely good news: most of the anxiety English speakers bring to the Korean past — "how do I say have?" — dissolves the moment you accept that one form does both jobs and lets context sort out which one is meant.

One marker, two English tenses

갔어요 is "went" and "has gone." 먹었어요 is "ate" and "have eaten." Which English tense fits is decided by the situation and by adverbs, never by a change in the Korean verb.

In 밥 먹었어요? the natural English is the perfect "Have you eaten?" — a question about your current state (are you fed?). In 어제 친구를 만났어요 the adverb 어제 "yesterday" pins it to a specific past event, so English uses the simple past. Same Korean marker; the context picks the English tense.

The allomorphy: 았 vs 었 vs 했

The marker has three surface shapes, chosen by the stem's last vowel — the same vowel-harmony logic as everywhere else in the language.

For the full mechanics of forming the polite past (-았어요/었어요), including contractions like 가 + 았어요 → 갔어요, see the past tense -았/었어요.

The resultant reading: past marker, present meaning

Here is the subtlety that catches even intermediate learners. With a set of verbs that describe a change into a lasting state, -았/었- does not report a past event — it reports the present state that resulted from it. 결혼했어요 is not primarily "I got married (once, in the past)"; it is "I am married (now)."

Think of what these have in common: getting married, coming to resemble, coming to understand — each is a transition into a state that still holds. Korean marks the transition with -았/었-, and the lasting state is what you actually mean. 알았어요 is the everyday "OK / got it" precisely because it says "I have (just now) come to know" — a present understanding. The same logic explains 갔어요 in a sentence like:

This is not merely "he went at some point"; it says he departed and, as a result, is not here now. The result is the point.

Why English speakers overthink this

Because English splits "ate" from "have eaten" and wires the perfect together with have + past participle, learners instinctively look for a matching Korean auxiliary and try to build one. There isn't one to build. The clean way to internalize it: Korean tense answers "past or non-past?" and leaves the finer perfect/simple-past distinction to context and adverbs. Where English would say "have already left," Korean says 벌써 갔어요 — the adverb 벌써 carries "already," and -았/었- carries "past/complete." This division of labor is covered further on 아직 vs 벌써 / 이미.

Two neighbors of this construction deserve their own pages, and you should keep them distinct from the plain -았/었-:

• The doubled -았었- (갔었어요) adds a "no longer the case" flavor — see -았었-: discontinued past. Do not use it as a general "perfect."
• The experiential -(으)ㄴ 적이 있다 (간 적이 있어요 "have ever been") is a separate noun construction — see -(으)ㄴ 적이 있다.

Common Mistakes

1. Trying to build a perfect with a "have"-style auxiliary. There is no 'have.' Don't calque "I have eaten" as ×먹어 있다 — the plain -았/었- is the perfect.

2. Using the present for a resultant state like "I'm married." 결혼하다 in the present means the event of getting married; the state of being married is the -았/었- form.

3. Using the present of 닮다 for "resemble." The stative "resembles" is carried by 닮았-, not the present 닮아요.

4. Reaching for the doubled -았었- as a general perfect. For a plain "I ate / I've eaten," use single -았/었-; the doubled form adds "and it's no longer so."

Key Takeaways

• -았/었- is both the simple past and the present perfect — 먹었어요 = "ate" and "have eaten." There is no separate 'have.'
• Which English tense fits is decided by context and adverbs (아직, 벌써, 방금), not by any change in the Korean verb.
• Allomorphy: ㅏ/ㅗ → 았 (갔다, 왔다), other vowels → 었 (먹었다, 읽었다), 하- → 했.
• With change-of-state/stative verbs, -았/었- describes a present result: 결혼했어요 "am married," 닮았어요 "resemble," 알았어요 "got it."
• Keep it distinct from the doubled -았었- ("no longer so") and the experiential -(으)ㄴ 적이 있다 ("have ever").