Past tense (~past)

The past tense in Korean is fundamentally different from English because it's not just about *when* something happened—it's about aspectual completion. In English, you say "I ate" or "I have eaten," but you're still thinking about the same action. In Korean, 먹었다 literally marks that an action has moved into the past and is complete. This is called the perfective aspect.

The two suffixes, 았 and 었, exist because of vowel harmony—a core feature of Korean where sounds must fit together naturally. If the verb stem's last vowel is ㅏ or ㅗ (bright vowels), you use 았. If it ends in any other vowel, you use 었. This isn't a rule to memorize as much as it's Korean's natural pronunciation rhythm. English speakers often want to memorize which verbs take which ending, but Korean speakers don't think that way—they simply *feel* which one sounds right, just like you naturally know "I go" sounds better than "I goes."

What makes this tricky for English speakers: Korean doesn't have separate words like "have" to mark the past. You don't say "I have eaten rice" (밥을 먹은 것이 있어요). Instead, you just say 밥을 먹었어요—the suffix itself carries the entire meaning of "completed action in the past." Once you say 먹었어요, the listener automatically understands it's done, finished, and in the past. This is more concise and direct than English's helper-verb system.