Adjectives · ㅂ irregular

무섭다 conjugation

to be scary; to be afraid · museopda · sounds like [무섭따]

Short answer: “Scary” in Korean is 무섭다 (museopda), which also means to be afraid. Polite present: 무서워요 (museowoyo); past: 무서웠어요 (museowosseoyo); future: 무서울 거예요. It is a ㅂ irregular adjective.

Present무서워요[무서워요] · museowoyo
Past무서웠어요[무서워써요] · museowosseoyo
Future무서울 거예요[무서울 꺼예요] · museoul geoyeyo
Negative안 무서워요[안 무서워요] · an museowoyo

무섭다 in sentences

공포 영화는 무서워요.Horror films are scary.
저는 개가 무서워요.I’m scared of dogs.

All forms of 무섭다

Present
Polite (해요) is the everyday safe choice; formal (합니다) is for news, announcements and work; casual (반말) is for close friends and younger people.
Form	Korean	Sounds like	Romanized
polite-아/어요	무서워요	[무서워요]	museowoyo
formal-(스)ㅂ니다	무섭습니다	[무섭씀니다]	museopseumnida
casual-아/어	무서워	[무서워]	museowo
plain (written)-다	무섭다	[무섭따]	museopda
formal question-(스)ㅂ니까?	무섭습니까?	[무섭씀니까]	museopseumnikka?

Past
Form	Korean	Sounds like	Romanized
polite-았/었어요	무서웠어요	[무서워써요]	museowosseoyo
formal-았/었습니다	무서웠습니다	[무서웓씀니다]	museowotseumnida
casual-았/었어	무서웠어	[무서워써]	museowosseo
plain (written)-았/었다	무서웠다	[무서웓따]	museowotda

Future
Form	Korean	Sounds like	Romanized
polite — will probably be-(으)ㄹ 거예요	무서울 거예요	[무서울 꺼예요]	museoul geoyeyo
formal-(으)ㄹ 겁니다	무서울 겁니다	[무서울 껌니다]	museoul geomnida
casual-(으)ㄹ 거야	무서울 거야	[무서울 꺼야]	museoul geoya

Negative
Form	Korean	Sounds like	Romanized
not (short)안 …	안 무서워요	[안 무서워요]	an museowoyo
did not안 …았/었어요	안 무서웠어요	[안 무서워써요]	an museowosseoyo
not (long)-지 않아요	무섭지 않아요	[무섭찌 아나요]	museopji anayo

Honorific
Add -(으)시- when the subject is someone you respect (a teacher, a customer, an older person) — not yourself.
Form	Korean	Sounds like	Romanized
honorific — present-(으)세요	무서우세요	[무서우세요]	museouseyo
honorific — past-(으)셨어요	무서우셨어요	[무서우셔써요]	museousyeosseoyo
honorific — formal-(으)십니다	무서우십니다	[무서우심니다]	museousimnida

Connecting
Form	Korean	Sounds like	Romanized
… and-고	무섭고	[무섭꼬]	museopgo
… so / and then-아/어서	무서워서	[무서워서]	museowoseo
if …-(으)면	무서우면	[무서우면]	museoumyeon
… but-지만	무섭지만	[무섭찌만]	museopjiman
because …-(으)니까	무서우니까	[무서우니까]	museounikka
… and / but (background)-(으)ㄴ데	무서운데	[무서운데]	museounde
even if …-아/어도	무서워도	[무서워도]	museowodo
while …-(으)면서	무서우면서	[무서우면서]	museoumyeonseo

Describing a noun
These go before a noun: “the food (that) I ate”, “a cold day”.
Form	Korean	Sounds like	Romanized
(that is) …-(으)ㄴ	무서운	[무서운]	museoun
(that) will …-(으)ㄹ	무서울	[무서울]	museoul

Useful patterns
Form	Korean	Sounds like	Romanized
can be …-(으)ㄹ 수 있어요	무서울 수 있어요	[무서울 쑤 이써요]	museoul su isseoyo
cannot be …-(으)ㄹ 수 없어요	무서울 수 없어요	[무서울 쑤 업써요]	museoul su eopseoyo
have to be …-아/어야 해요	무서워야 해요	[무서워야 해요]	museowoya haeyo
it’s OK if it’s …-아/어도 돼요	무서워도 돼요	[무서워도 돼요]	museowodo dwaeyo
…ly (adverb)-게	무섭게	[무섭께]	museopge
becomes …-아/어지다	무서워져요	[무서워저요]	museowojeoyo
…ing (noun)-기	무섭기	[무섭끼]	museopgi

How 무섭다 changes

ㅂ irregular: before a vowel, ㅂ turns into 우 — so 무섭 + 어 → 무서워요, and -(으) endings use 우: 무서우면, 무서울. Before a consonant the ㅂ stays: 무섭습니다, 무섭고. Not every ㅂ word does this — 입다 → 입어요 and 잡다 → 잡아요 are regular.

How every verb type works → · Why it sounds like that →

Questions

How do you say “scary” in Korean?

“Scary” is 무섭다 (museopda), pronounced [무섭따]. In a sentence: 공포 영화는 무서워요. — Horror films are scary.

What is the past tense of 무섭다?

무서웠어요 (museowosseoyo) is the polite past tense of 무섭다 (“to be scary”). Formal: 무서웠습니다; casual: 무서웠어.

How do you say 무섭다 politely?

Everyday polite: 무서워요 (museowoyo). Formal: 무섭습니다. Casual, with close friends: 무서워.

How do you say “not scary” in Korean?

안 무서워요 or 무섭지 않아요. Both mean the same; the first is more common in speech.

Is 무섭다 irregular?

Yes — ㅂ irregular: before a vowel, ㅂ turns into 우 — so 무섭 + 어 → 무서워요, and -(으) endings use 우: 무서우면, 무서울. Before a consonant the ㅂ stays: 무섭습니다, 무섭고. Not every ㅂ word does this — 입다 → 입어요 and 잡다 → 잡아요 are regular.

More ㅂ irregular words like 무섭다

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Forms follow 한글 맞춤법 (Korean spelling rules); pronunciation follows 표준 발음법 and romanization follows 국어의 로마자 표기법 (Revised Romanization). Last updated October 16, 2026. How we check