Core Grammar Rule: Past Tense Marker -았/었-
In Korean, you change the verb or adjective ending to show that an action or state occurred in the past. The past tense marker -았/었- is attached directly to the stem of the verb or adjective.
Meaning & Usage
Meaning: It's equivalent to the simple past tense in English (e.g., "ate," "was," "studied"). It indicates a completed action or a state that was true in the past.
When to use: Use it whenever you're talking about something that has already happened, whether it was yesterday, last week, or ten years ago. It's fundamental for telling stories, sharing experiences, or explaining past events.
Conjugation Rules
Rule: The choice between -았- and -었- depends on the last vowel of the verb/adjective stem. If the stem is a 하다 verb, it becomes -했-.
Last vowel is ㅏ or ㅗ: Attach -았어요 (polite) or -았어 (casual). Example: 가다 (to go) → 가 + 았어요 → 갔어요 (went). 보다 (to see) → 보 + 았어요 → 봤어요 (saw).
Last vowel is NOT ㅏ or ㅗ: Attach -었어요 (polite) or -었어 (casual). Example: 먹다 (to eat) → 먹 + 었어요 → 먹었어요 (ate). 읽다 (to read) → 읽 + 었어요 → 읽었어요 (read).
하다 verbs: These verbs always change to -했어요 (polite) or -했어 (casual). Example: 공부하다 (to study) → 공부했어요 (studied). 일하다 (to work) → 일했어요 (worked).
Vowel ㅏ/ㅗ: + -았- / Other Vowels: + -었- / 하다 Verbs: -했-
Time Particle ~에
The particle ~에 is essential for specifying when something happens. It attaches to nouns related to time, like days of the week, dates, and specific times of day.
Usage with Days and Dates
Context: When you want to pinpoint an event on a specific day or date, you attach ~에 directly to the noun. This is similar to using "on" in English (e.g., on Monday, on the 5th).
Example: 저는 토요일에 영화를 봤어요. (I watched a movie on Saturday.) / 10월 9일에 한글날이에요. (It's Hangeul Day on October 9th.)
When NOT to Use ~에
Context: While ~에 is used for specific points in time, it is generally NOT used with relative time words like 어제 (yesterday), 오늘 (today), 내일 (tomorrow), or 언제 (when). These words function as adverbs on their own and don't require a particle.