못쓰다 Korean verb conjugation

to be unusable

Every form of 못쓰다 across the four speech levels. It is 으 irregular — The stem 으 drops before a vowel ending: 쓰다 → 써요.

기본형Principal parts

The four forms the dictionary prints. Every other form on this page is derived from them.

관형사형Modifier
못쓰는
아/어Infinitive
못써
-으니Since
못쓰니
합니다Formal
못씁니다

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.

해요체Polite합니다체Formal해체Casual한다체Plain
서술Statement 못써요못씁니다못써못쓴다

과거Past

해요체Polite합니다체Formal해체Casual한다체Plain
서술Statement 못썼어요못썼습니다못썼어못썼다

미래·추측Future & presumptive

해요체Polite합니다체Formal해체Casual한다체Plain
-겠-Will / must be 못쓰겠어요못쓰겠습니다못쓰겠어못쓰겠다
-을 것이다Going to 못쓸 거예요못쓸 것입니다못쓸 거야못쓸 것이다

의문Questions

해요체Polite합니다체Formal해체Casual한다체Plain
현재Present 못써요?못씁니까?못써?못쓰니?
과거Past 못썼어요?못썼습니까?못썼어?못썼니?

명령Commands

해요체Polite합니다체Formal해체Casual한다체Plain
명령Do it 못쓰세요못쓰십시오못써못써라
청유Let's 못써요못씁시다못써못쓰자

부정Negation

해요체Polite합니다체Formal해체Casual한다체Plain
Not (short) 안 못써요안 못씁니다안 못써안 못쓴다
-지 않다Not (long) 못쓰지 않아요못쓰지 않습니다못쓰지 않아못쓰지 않는다
Cannot 못 못써요못 못씁니다못 못써못 못쓴다

높임Honorific

해요체Polite합니다체Formal해체Casual한다체Plain
현재Present 못쓰세요못쓰십니다못쓰셔못쓰신다
과거Past 못쓰셨어요못쓰셨습니다못쓰셨어못쓰셨다

관형사형Modifying a noun

현재Present
못쓰는
과거Past
못쓴
미래Future
못쓸
회상Used to
못쓰던

연결Joining clauses

-고and
못쓰고
-게-ly / so that
못쓰게
-어서so / and then
못써서
-으니까since
못쓰니까
-으면if / when
못쓰면
-지만but
못쓰지만
-는데and / but (setting up)
못쓰는데
-어도even if
못써도

진행In progress

해요체Polite합니다체Formal해체Casual한다체Plain
현재Is doing 못쓰고 있어요못쓰고 있습니다못쓰고 있어못쓰고 있다
과거Was doing 못쓰고 있었어요못쓰고 있었습니다못쓰고 있었어못쓰고 있었다

문형Sentence patterns

How the dictionary says this verb is used. The numbers are slots: 1 is the subject, 2 the object.

예문In real sentences

From the dictionary, each with its translation.

그렇게 쓸데없이 성을 내면 못써.

It's no good getting angry for no apparent reason like that.

안돼! 안돼! 그러면 못써!

Voice: No. No. You're not to do that. No.

거짓말하면 못 써.

People don't need to be lied to.

자꾸 이러면은 못 쓰네

Come on, don't be that way.

자주 묻는 질문Common questions

How do you conjugate 못쓰다 in Korean?

못쓰다 (to be unusable) is 못써요 in the polite 해요체, 못씁니다 in formal 합니다체, 못써 in casual 반말 and 못쓴다 in the plain written style. The past is 못썼어요.

What is the past tense of 못쓰다?

못썼어요 in everyday polite speech, 못썼습니다 formally. It is built from the 아/어 form 못써 plus ㅆ, which is why an irregular stem shows its irregularity here.

Is 못쓰다 irregular?

Yes — it is 으 irregular (으 불규칙). The stem 으 drops before a vowel ending: 쓰다 → 써요. That is why the stem looks different in 못써 and 못쓰니 but unchanged in 못씁니다.

What TOPIK level is 못쓰다?

It carries no TOPIK grade. That is a fact about the published word lists rather than about the word — it conjugates by exactly the same rules as everything else.

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.