확실하다

to be certain

Principal parts

관형사형Modifier
확실한
아/어Infinitive
확실해
-으니Since
확실하니
합니다Formal
확실합니다

Present

해요체Polite합니다체Formal해체Casual한다체Plain
서술Statement 확실해요확실합니다확실해확실하다

Past

해요체Polite합니다체Formal해체Casual한다체Plain
서술Statement 확실했어요확실했습니다확실했어확실했다

Future & presumptive

해요체Polite합니다체Formal해체Casual한다체Plain
-겠-Will / must be 확실하겠어요확실하겠습니다확실하겠어확실하겠다
-을 것이다Going to 확실할 거예요확실할 것입니다확실할 거야확실할 것이다

Questions

해요체Polite합니다체Formal해체Casual한다체Plain
현재Present 확실해요?확실합니까?확실해?확실하니?
과거Past 확실했어요?확실했습니까?확실했어?확실했니?

Negation

해요체Polite합니다체Formal해체Casual한다체Plain
안Not (short) 안 확실해요안 확실합니다안 확실해안 확실하다
-지 않다Not (long) 확실하지 않아요확실하지 않습니다확실하지 않아확실하지 않다

Honorific

해요체Polite합니다체Formal해체Casual한다체Plain
현재Present 확실하세요확실하십니다확실하셔확실하시다
과거Past 확실하셨어요확실하셨습니다확실하셨어확실하셨다

Modifying a noun

현재Present
확실한
과거Past
확실한
미래Future
확실할
회상Used to
확실하던

Joining 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

Sentence patterns

In real sentences

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.

Common 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.