How does tense work in Korean?
Korean marks past with 았/었 inserted before the ending, and expresses future most often with 을 거예요. The present covers both simple and habitual meaning. The complication is that 았/었 marks completion rather than past time as such, so it appears in sentences describing a present state that resulted from an earlier change.
Past inserts 았/었
The marker goes between the stem and the ending, and follows the same vowel rule as the present: 았 after ㅏ or ㅗ, 었 otherwise. Contractions follow automatically where vowels meet.
먹어요 → 먹었어요
meogeoyo → meogeosseoyo
eat → ate
가요 → 갔어요
gayo → gasseoyo
go → went
가 + 았 contracts to 갔.
해요 → 했어요
haeyo → haesseoyo
do → did
Future is usually 을 거예요
Korean has more than one future construction and they are not interchangeable. 을 거예요 is the ordinary future or intention. 겠 carries conjecture or strong intention and is common in fixed phrases rather than as a plain future.
갈 거예요
gal geoyeyo
will go / am going to go
맛있겠어요
masitgesseoyo
That looks delicious.
겠 as conjecture, not future.
알겠습니다
algesseumnida
Understood.
A set phrase.
Completion is not the same as past
This is the part that surprises learners. 았/었 marks that a change has completed, so it appears where English would use a present tense — because the resulting state is what matters. 결혼했어요 describes being married now, not an event in the past.
결혼했어요.
gyeolhonhaesseoyo
I'm married.
Not I got married, in most contexts.
앉았어요.
anjasseoyo
I'm sitting down.
The sitting completed; the state continues.
밥 먹고 있어요.
bap meokgo isseoyo
I'm eating.
고 있다 for a genuinely ongoing action.
Common mistakes
결혼해요. (meaning: I am married)
결혼했어요.
The present would mean you are getting married, as an event happening now or scheduled. The completed form is what describes the resulting married state.
먹었고 있어요
먹고 있어요
The progressive 고 있다 attaches to the plain stem. Past and progressive do not stack in that order.
갈 겠어요
갈 거예요
겠 and 을 거예요 are separate constructions and cannot be combined. For a plain future, use 을 거예요.
Frequently asked questions
Does Korean really have only three tenses?
Broadly yes — past, present and future — but aspect does a lot of additional work through endings like 고 있다 for the progressive and 아/어 있다 for a resulting state. Those carry distinctions that English handles with tense.
When do I use 고 있다 rather than the plain present?
When the action is genuinely in progress right now. The plain present covers habitual and general statements, so 먹어요 can mean I eat, while 먹고 있어요 means I am eating at this moment.
Why does 앉았어요 mean I'm sitting?
Because 았/었 marks the completion of the change — the act of sitting down finished, and you are now in the resulting state. Several posture and state verbs behave this way, and translating them as past tense produces the wrong meaning.