나쁘다 conjugation

to be bad · nappeuda · sounds like [나쁘다]

Short answer: “Bad” in Korean is 나쁘다 (nappeuda). Polite present: 나빠요 (nappayo); past: 나빴어요 (nappasseoyo); future: 나쁠 거예요. It is regular, but its ㅡ drops before 아/어.

Present나빠요[나빠요] · nappayo
Past나빴어요[나빠써요] · nappasseoyo
Future나쁠 거예요[나쁠 꺼예요] · nappeul geoyeyo
Negative안 나빠요[안 나빠요] · an nappayo

Opposite: 좋다 — to be good

나쁘다 in sentences

오늘은 공기가 나빠요.The air quality is bad today.
어제는 기분이 나빴어요.I was in a bad mood yesterday.

All forms of 나쁘다

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	나빠요	[나빠요]	nappayo
formal-(스)ㅂ니다	나쁩니다	[나쁨니다]	nappeumnida
casual-아/어	나빠	[나빠]	nappa
plain (written)-다	나쁘다	[나쁘다]	nappeuda
formal question-(스)ㅂ니까?	나쁩니까?	[나쁨니까]	nappeumnikka?

Past
Form	Korean	Sounds like	Romanized
polite-았/었어요	나빴어요	[나빠써요]	nappasseoyo
formal-았/었습니다	나빴습니다	[나빧씀니다]	nappatseumnida
casual-았/었어	나빴어	[나빠써]	nappasseo
plain (written)-았/었다	나빴다	[나빧따]	nappatda

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

Negative
Form	Korean	Sounds like	Romanized
not (short)안 …	안 나빠요	[안 나빠요]	an nappayo
did not안 …았/었어요	안 나빴어요	[안 나빠써요]	an nappasseoyo
not (long)-지 않아요	나쁘지 않아요	[나쁘지 아나요]	nappeuji 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	나쁘세요	[나쁘세요]	nappeuseyo
honorific — past-(으)셨어요	나쁘셨어요	[나쁘셔써요]	nappeusyeosseoyo
honorific — formal-(으)십니다	나쁘십니다	[나쁘심니다]	nappeusimnida

Connecting
Form	Korean	Sounds like	Romanized
… and-고	나쁘고	[나쁘고]	nappeugo
… so / and then-아/어서	나빠서	[나빠서]	nappaseo
if …-(으)면	나쁘면	[나쁘면]	nappeumyeon
… but-지만	나쁘지만	[나쁘지만]	nappeujiman
because …-(으)니까	나쁘니까	[나쁘니까]	nappeunikka
… and / but (background)-(으)ㄴ데	나쁜데	[나쁜데]	nappeunde
even if …-아/어도	나빠도	[나빠도]	nappado
while …-(으)면서	나쁘면서	[나쁘면서]	nappeumyeonseo

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	나쁜	[나쁜]	nappeun
(that) will …-(으)ㄹ	나쁠	[나쁠]	nappeul

Useful patterns
Form	Korean	Sounds like	Romanized
can be …-(으)ㄹ 수 있어요	나쁠 수 있어요	[나쁠 쑤 이써요]	nappeul su isseoyo
cannot be …-(으)ㄹ 수 없어요	나쁠 수 없어요	[나쁠 쑤 업써요]	nappeul su eopseoyo
have to be …-아/어야 해요	나빠야 해요	[나빠야 해요]	nappaya haeyo
it’s OK if it’s …-아/어도 돼요	나빠도 돼요	[나빠도 돼요]	nappado dwaeyo
…ly (adverb)-게	나쁘게	[나쁘게]	nappeuge
becomes …-아/어지다	나빠져요	[나빠저요]	nappajeoyo
…ing (noun)-기	나쁘기	[나쁘기]	nappeugi

How 나쁘다 changes

The ㅡ in 나쁘다 drops before 아/어: 나빠요, 나빴어요. The vowel that replaces it follows the syllable before (아 after ㅏ or ㅗ, otherwise 어). With other endings ㅡ stays: 나쁘면, 나쁩니다.

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

Questions

How do you say “bad” in Korean?

“Bad” is 나쁘다 (nappeuda), pronounced [나쁘다]. In a sentence: 오늘은 공기가 나빠요. — The air quality is bad today.

What is the past tense of 나쁘다?

나빴어요 (nappasseoyo) is the polite past tense of 나쁘다 (“to be bad”). Formal: 나빴습니다; casual: 나빴어.

How do you say 나쁘다 politely?

Everyday polite: 나빠요 (nappayo). Formal: 나쁩니다. Casual, with close friends: 나빠.

How do you say “not bad” in Korean?

안 나빠요 or 나쁘지 않아요. Both mean the same; the first is more common in speech.

Is 나쁘다 irregular?

No. The ㅡ in 나쁘다 drops before 아/어: 나빠요, 나빴어요. The vowel that replaces it follows the syllable before (아 after ㅏ or ㅗ, otherwise 어). With other endings ㅡ stays: 나쁘면, 나쁩니다.

More ㅡ-stem words like 나쁘다

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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