크다 conjugation

to be big; tall · keuda · sounds like [크다]

Short answer: “Big” in Korean is 크다 (keuda), which also means tall. Polite present: 커요 (keoyo); past: 컸어요 (keosseoyo); future: 클 거예요. It is regular, but its ㅡ drops before 아/어.

Present커요[커요] · keoyo
Past컸어요[커써요] · keosseoyo
Future클 거예요[클 꺼예요] · keul geoyeyo
Negative안 커요[안 커요] · an keoyo

Opposite: 작다 — to be small

크다 in sentences

이 방은 커요.This room is big.
더 큰 사이즈 있어요?Do you have a bigger size?

All forms of 크다

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	커요	[커요]	keoyo
formal-(스)ㅂ니다	큽니다	[큼니다]	keumnida
casual-아/어	커	[커]	keo
plain (written)-다	크다	[크다]	keuda
formal question-(스)ㅂ니까?	큽니까?	[큼니까]	keumnikka?

Past
Form	Korean	Sounds like	Romanized
polite-았/었어요	컸어요	[커써요]	keosseoyo
formal-았/었습니다	컸습니다	[컫씀니다]	keotseumnida
casual-았/었어	컸어	[커써]	keosseo
plain (written)-았/었다	컸다	[컫따]	keotda

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

Negative
Form	Korean	Sounds like	Romanized
not (short)안 …	안 커요	[안 커요]	an keoyo
did not안 …았/었어요	안 컸어요	[안 커써요]	an keosseoyo
not (long)-지 않아요	크지 않아요	[크지 아나요]	keuji 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	크세요	[크세요]	keuseyo
honorific — past-(으)셨어요	크셨어요	[크셔써요]	keusyeosseoyo
honorific — formal-(으)십니다	크십니다	[크심니다]	keusimnida

Connecting
Form	Korean	Sounds like	Romanized
… and-고	크고	[크고]	keugo
… so / and then-아/어서	커서	[커서]	keoseo
if …-(으)면	크면	[크면]	keumyeon
… but-지만	크지만	[크지만]	keujiman
because …-(으)니까	크니까	[크니까]	keunikka
… and / but (background)-(으)ㄴ데	큰데	[큰데]	keunde
even if …-아/어도	커도	[커도]	keodo
while …-(으)면서	크면서	[크면서]	keumyeonseo

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	큰	[큰]	keun
(that) will …-(으)ㄹ	클	[클]	keul

Useful patterns
Form	Korean	Sounds like	Romanized
can be …-(으)ㄹ 수 있어요	클 수 있어요	[클 쑤 이써요]	keul su isseoyo
cannot be …-(으)ㄹ 수 없어요	클 수 없어요	[클 쑤 업써요]	keul su eopseoyo
have to be …-아/어야 해요	커야 해요	[커야 해요]	keoya haeyo
it’s OK if it’s …-아/어도 돼요	커도 돼요	[커도 돼요]	keodo dwaeyo
…ly (adverb)-게	크게	[크게]	keuge
becomes …-아/어지다	커져요	[커저요]	keojeoyo
…ing (noun)-기	크기	[크기]	keugi

How 크다 changes

The ㅡ in 크다 drops before 아/어: 커요, 컸어요. The vowel that replaces it follows the syllable before (아 after ㅏ or ㅗ, otherwise 어). With other endings ㅡ stays: 크면, 큽니다.

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

Questions

How do you say “big” in Korean?

“Big” is 크다 (keuda), pronounced [크다]. In a sentence: 이 방은 커요. — This room is big.

What is the past tense of 크다?

컸어요 (keosseoyo) is the polite past tense of 크다 (“to be big”). Formal: 컸습니다; casual: 컸어.

How do you say 크다 politely?

Everyday polite: 커요 (keoyo). Formal: 큽니다. Casual, with close friends: 커.

How do you say “not big” in Korean?

안 커요 or 크지 않아요. Both mean the same; the first is more common in speech.

Is 크다 irregular?

No. The ㅡ in 크다 drops before 아/어: 커요, 컸어요. The vowel that replaces it follows the syllable before (아 after ㅏ or ㅗ, otherwise 어). With other endings ㅡ stays: 크면, 큽니다.

More ㅡ-stem words like 크다

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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