Almost every mistake learners make with 것 같다 is really a mistake about the modifier ending in front of 것 — the little -는 / -(으)ㄴ / -(으)ㄹ that sets the tense. Master this one table and the errors evaporate. The tricky part is that Korean sorts predicates into action verbs and descriptive verbs (adjectives), and the two classes assign these endings differently. So we take them one class at a time.
Verbs: -는 / -(으)ㄴ / -(으)ㄹ
For an action verb, the three modifiers line up cleanly with present, past, and future:
| Tense | Ending | 먹다 (eat) | 가다 (go) | 만들다 (make, ㄹ-stem) |
|---|---|---|---|---|
| Present | -는 | 먹는 것 같다 (meongneun) | 가는 것 같다 (ganeun) | 만드는 것 같다 (mandeuneun) |
| Past | -(으)ㄴ | 먹은 것 같다 (meogeun) | 간 것 같다 (gan) | 만든 것 같다 (mandeun) |
| Future | -(으)ㄹ | 먹을 것 같다 (meogeul) | 갈 것 같다 (gal) | 만들 것 같다 (mandeul) |
동생이 지금 자는 것 같아요.
dongsaeng-i jigeum janeun geot gatayo
My little brother seems to be sleeping right now.
형이 벌써 밥을 먹은 것 같아요.
hyeong-i beolsseo babeul meogeun geot gatayo
My older brother seems to have already eaten.
이따가 비가 올 것 같아요.
ittaga biga ol geot gatayo
It looks like it'll rain later.
Adjectives: -(으)ㄴ for the present
Here is the twist. An adjective's present state is marked with -(으)ㄴ — the very ending that means past for a verb. 좋다 → 좋은 것 같다 ("seems good," right now), never ×좋는. The recalled or remembered past state usually uses -았/었던, and the future is -(으)ㄹ.
| Tense | Ending | 좋다 (be good) | 예쁘다 (be pretty) |
|---|---|---|---|
| Present state | -(으)ㄴ | 좋은 것 같다 (joeun) | 예쁜 것 같다 (yeppeun) |
| Recalled past | -았/었던 | 좋았던 것 같다 (joatdeon) | 예뻤던 것 같다 (yeppeotdeon) |
| Future | -(으)ㄹ | 좋을 것 같다 (joeul) | 예쁠 것 같다 (yeppeul) |
저 가방 되게 비싼 것 같아요.
jeo gabang doege bissan geot gatayo
That bag looks pretty expensive.
오늘 날씨가 좋은 것 같아요.
oneul nalssiga joeun geot gatayo
The weather seems nice today.
어렸을 때 여기가 더 좋았던 것 같아요.
eoryeosseul ttae yeogiga deo joatdeon geot gatayo
I feel like this place was nicer when I was little.
Why -(으)ㄴ marks present on an adjective but past on a verb
This looks arbitrary until you see what -(으)ㄴ actually does: it marks a realized, settled state. For an action verb, the realized result of the action is a past event — 먹은 = "having eaten." For a descriptive verb, the realized state simply is the present condition — 좋은 = "being (in a state of) good." Same ending, same underlying "settled state" logic; it just lands on a different point in time depending on whether the predicate names an event or a quality. The full reasoning is on -(으)ㄴ adjective vs. -는 verb modifiers.
Nouns: 인 / 이었던 / 일
A noun rides the copula 이다 into the modifier slot:
| Tense | Form | 학생 (student) | 친구 (friend) |
|---|---|---|---|
| Present | 인 | 학생인 것 같다 (haksaeng-in) | 친구인 것 같다 (chinguin) |
| Past | 이었/였던 | 학생이었던 것 같다 (haksaeng-ieotdeon) | 친구였던 것 같다 (chinguyeotdeon) |
| Future | 일 | 학생일 것 같다 (haksaeng-il) | 친구일 것 같다 (chinguil) |
저분이 새 팀장님인 것 같아요.
jeobuni sae timjangnimin geot gatayo
That person seems to be the new team leader.
예전엔 여기가 학교였던 것 같아요.
yejeonen yeogiga hakgyoyeotdeon geot gatayo
I think this place used to be a school.
The allomorphy: 은/을 vs. ㄴ/ㄹ, and the ㄹ-stem drop
The endings -(으)ㄴ and -(으)ㄹ take the fuller 은/을 after a consonant batchim, and bare ㄴ/ㄹ after a vowel:
- 먹다 (batchim) → 먹은 / 먹을; 가다 (vowel) → 간 / 갈.
ㄹ-stem verbs drop their ㄹ before -는 and -(으)ㄴ, and merge it into -(으)ㄹ:
- 만들다 → 만드는 (ㄹ drops before ㄴ), 만든 (ㄹ drops before ㄴ), 만들 (ㄹ stays as the ㄹ ending).
- 살다 → 사는 것 같다, 산 것 같다, 살 것 같다.
아이가 뭘 만드는 것 같아요.
aiga mwol mandeuneun geot gatayo
The kid seems to be making something.
Two independent tense slots
Here is the subtlety that separates fluent use from textbook use. There are two places tense can live, and they mean different things:
- The modifier ending fixes when the inner event happens.
- Conjugating 같다 itself (같았어요) fixes when the judgement was made.
So 아픈 것 같아요 = "he seems sick (I judge now)," while 아픈 것 같았어요 = "he seemed sick (I judged so at the time)." The sickness is present in both; what moves is the moment of your guessing.
아까는 좀 아픈 것 같았어요.
akkaneun jom apeun geot gatasseoyo
Earlier he seemed a bit sick (that was my impression then).
Common Mistakes
Mistake 1 — Verb -는 on an adjective. Adjectives take -(으)ㄴ for the present.
❌ 방이 넓는 것 같아요.
Wrong — 넓다 is an adjective; use 넓은.
✅ 방이 넓은 것 같아요.
bang-i neolbeun geot gatayo
The room seems spacious.
Mistake 2 — Adjective/past -(으)ㄴ on a verb you mean as present. For an ongoing action, use -는.
❌ 저 사람 지금 밥을 먹은 것 같아요.
Says 'seems to have eaten,' not 'seems to be eating now.'
✅ 저 사람 지금 밥을 먹는 것 같아요.
jeo saram jigeum babeul meongneun geot gatayo
That person seems to be eating right now.
Mistake 3 — Not dropping ㄹ on a ㄹ-stem.
❌ 아이가 뭘 만들는 것 같아요.
Wrong — 만들다 drops ㄹ before -는: 만드는.
✅ 아이가 뭘 만드는 것 같아요.
aiga mwol mandeuneun geot gatayo
The kid seems to be making something.
Mistake 4 — Wrong allomorph after a batchim. The past of 먹다 is 먹은 (은 after the consonant), not a bare ㄴ.
❌ 벌써 다 먹ㄴ 것 같아요.
Wrong — a consonant stem needs 은: 먹은.
✅ 벌써 다 먹은 것 같아요.
beolsseo da meogeun geot gatayo
Seems it's all been eaten already.
Mistake 5 — Stranding a past event on 같다.
❌ 아까 비가 오는 것 같았어요.
Means 'earlier it seemed to be raining,' not 'it seems it rained.'
✅ 비가 온 것 같아요.
biga on geot gatayo
It seems it rained.
Key Takeaways
- Verbs: -는 (present) · -(으)ㄴ (past) · -(으)ㄹ (future).
- Adjectives: -(으)ㄴ (present state) · -았/었던 (recalled past) · -(으)ㄹ (future) — never verb -는.
- Nouns: 인 (present) · 이었/였던 (past) · 일 (future).
- Allomorphy: 은/을 after a batchim, ㄴ/ㄹ after a vowel; ㄹ-stems drop ㄹ before -는 and -(으)ㄴ.
- Two tense slots: the modifier fixes when the event was; conjugating 같다 (같았어요) fixes when you judged.
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Start learning Korean→Related Topics
- -(으)ㄴ/-는/-(으)ㄹ 것 같다: Seems / ProbablyTOPIK 3 — Korean's default device for guessing and softening — a clause is nominalized with 것 and compared to reality by 같다, with the tense carried on the modifier ending, not on 같다.
- 것 같다 as an Opinion Softener (Not Real Doubt)TOPIK 3 — Koreans use 것 같다 to downgrade a firm opinion into a polite personal impression — even about food they're tasting right now — where English would never say 'seems.'
- Degrees of Certainty: A Map of Korean ConjectureTOPIK 4 — A hub page ranking Korean's guessing endings from tentative to near-certain — and, more importantly, sorting them by evidential source, because Korean grammaticalises both how sure you are and where the guess came from.
- -는 듯하다 / -는 듯싶다: It Seems (Literary)TOPIK 5 — The bookish conjecture markers -는 듯하다 and -는 듯싶다 — near-synonyms of 것 같다 dressed for writing and refined speech — plus how to keep the conjectural 듯 apart from the manner comparison -듯이 'as if'.