One Stem, Three Time Contexts
Korean forms for present, past, and basic future contexts can be understood as related forms built from the same stem rather than as unrelated words.
Start with the dictionary form, identify the stem, and combine it with the element required for the target context. Contraction may change how part of the result appears on the surface.
The selected form and the surrounding context work together to show how the event is understood in time.
A Regular Consonant-Final Example
Let's take the regular verb 먹다 . Its stem is 먹- .
Present context: 먹- + -어요 → 먹어요
Past context: 먹- + -었어요 → 먹었어요
Basic future context: 먹- + -을 거예요 → 먹을 거예요
In these examples, the written stem 먹- remains clearly recognizable while a different element is selected for each context.
Vowel Stems and Contractions
When a stem ends in a vowel, the present and past endings often blend or contract with the stem.
The verb 가다
Present: 가 + 아요 → 가요
Past: 가 + 았어요 → 갔어요
Future: 가 + ㄹ 거예요 → 갈 거예요
The verb 보다
Present: 보 + 아요 → 봐요
Past: 보 + 았어요 → 봤어요
Future: 보 + ㄹ 거예요 → 볼 거예요
The 하다 Verbs
Verbs ending in 하다 follow their own highly consistent pattern across all three times.
Present: 하다 becomes 해요
Past: 하다 becomes 했어요
Future: 하다 becomes 할 거예요
For example, with 공부하다 :
Present: 공부해요
Past: 공부했어요
Future: 공부할 거예요
Common Mistake: Stacking Completed Forms
A common beginner mistake is starting from the completed 해요 -style form and then trying to add another time-related element.
Do not build 먹었어요 from the completed form 먹어요 . Return to 먹다 , identify the stem 먹- , and combine it with -었어요 : 먹- + -었어요 → 먹었어요 .
Build 먹을 거예요 from the same stem 먹- rather than stacking it onto 먹어요 .