확실하다 Korean adjective conjugation
to be certain
Every form of 확실하다 across the four speech levels. It is 여 irregular — 하다 and every verb built on it: 하다 → 하여 → 해요.
기본형Principal parts
The four forms the dictionary prints. Every other form on this page is derived from them.
- 관형사형Modifier
- 확실한
- 아/어Infinitive
- 확실해
- -으니Since
- 확실하니
- 합니다Formal
- 확실합니다
현재Present
The tense that does the most work. 해요체 is the one to learn first — it is polite without being formal, and it is what most conversation is in.
| 해요체Polite | 합니다체Formal | 해체Casual | 한다체Plain | |
|---|---|---|---|---|
| 서술Statement | 확실해요 | 확실합니다 | 확실해 | 확실하다 |
과거Past
| 해요체Polite | 합니다체Formal | 해체Casual | 한다체Plain | |
|---|---|---|---|---|
| 서술Statement | 확실했어요 | 확실했습니다 | 확실했어 | 확실했다 |
미래·추측Future & presumptive
| 해요체Polite | 합니다체Formal | 해체Casual | 한다체Plain | |
|---|---|---|---|---|
| -겠-Will / must be | 확실하겠어요 | 확실하겠습니다 | 확실하겠어 | 확실하겠다 |
| -을 것이다Going to | 확실할 거예요 | 확실할 것입니다 | 확실할 거야 | 확실할 것이다 |
의문Questions
| 해요체Polite | 합니다체Formal | 해체Casual | 한다체Plain | |
|---|---|---|---|---|
| 현재Present | 확실해요? | 확실합니까? | 확실해? | 확실하니? |
| 과거Past | 확실했어요? | 확실했습니까? | 확실했어? | 확실했니? |
부정Negation
| 해요체Polite | 합니다체Formal | 해체Casual | 한다체Plain | |
|---|---|---|---|---|
| 안Not (short) | 안 확실해요 | 안 확실합니다 | 안 확실해 | 안 확실하다 |
| -지 않다Not (long) | 확실하지 않아요 | 확실하지 않습니다 | 확실하지 않아 | 확실하지 않다 |
높임Honorific
| 해요체Polite | 합니다체Formal | 해체Casual | 한다체Plain | |
|---|---|---|---|---|
| 현재Present | 확실하세요 | 확실하십니다 | 확실하셔 | 확실하시다 |
| 과거Past | 확실하셨어요 | 확실하셨습니다 | 확실하셨어 | 확실하셨다 |
관형사형Modifying a noun
- 현재Present
- 확실한
- 과거Past
- 확실한
- 미래Future
- 확실할
- 회상Used to
- 확실하던
연결Joining clauses
- -고and
- 확실하고
- -게-ly / so that
- 확실하게
- -어서so / and then
- 확실해서
- -으니까since
- 확실하니까
- -으면if / when
- 확실하면
- -지만but
- 확실하지만
- -는데and / but (setting up)
- 확실한데
- -어도even if
- 확실해도
문형Sentence patterns
How the dictionary says this verb is used. The numbers are slots: 1 is the subject, 2 the object.
- 1이 확실하다
예문In real sentences
From the dictionary, each with its translation.
그 꼴을 보니 확실하군요
Sure didn't look like it.
가방, 당신 거 확실해요?
The bag, you sure it's yours?
그럼, 이건 확실한 건가요?
Now, is it definite or not?
네, 과학이 어떤 종류의 인간의 고통을 줄여놓은건 확실합니다.
Yes, to be sure, science has done much to push back certain types of human suffering.
자주 묻는 질문Common questions
How do you conjugate 확실하다 in Korean?
확실하다 (to be certain) is 확실해요 in the polite 해요체, 확실합니다 in formal 합니다체, 확실해 in casual 반말 and 확실하다 in the plain written style. The past is 확실했어요.
What is the past tense of 확실하다?
확실했어요 in everyday polite speech, 확실했습니다 formally. It is built from the 아/어 form 확실하여 plus ㅆ, which is why an irregular stem shows its irregularity here.
Is 확실하다 irregular?
Yes — it is 여 irregular (여 불규칙). 하다 and every verb built on it: 하다 → 하여 → 해요. That is why the stem looks different in 확실하여 and 확실하니 but unchanged in 확실합니다.
What TOPIK level is 확실하다?
4급 — TOPIK 4, upper intermediate.
Dictionary form, meaning, sentence patterns, examples and audio from the 국립국어원 한국어기초사전, used under CC BY-SA 2.0 KR.
Conjugations are generated by this site's own engine and checked against the 9,380 forms the dictionary publishes on every build.