Verbs · Regular

끓다 conjugation

to boil · kkeulta · sounds like [끌타]

Short answer: “To boil” in Korean is 끓다 (kkeulta). Polite present: 끓어요 (kkeureoyo); past: 끓었어요 (kkeureosseoyo); future: 끓을 거예요. It is regular.

Present끓어요[끄러요] · kkeureoyo
Past끓었어요[끄러써요] · kkeureosseoyo
Future끓을 거예요[끄를 꺼예요] · kkeureul geoyeyo
Negative안 끓어요[안 끄러요] · an kkeureoyo

끓다 in sentences

물이 끓어요.The water is boiling.
물이 끓으면 면을 넣으세요.When the water boils, add the noodles.

All forms of 끓다

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	끓어요	[끄러요]	kkeureoyo
formal-(스)ㅂ니다	끓습니다	[끌씀니다]	kkeulseumnida
casual-아/어	끓어	[끄러]	kkeureo
plain (written)-(느)ㄴ다	끓는다	[끌른다]	kkeulleunda
formal question-(스)ㅂ니까?	끓습니까?	[끌씀니까]	kkeulseumnikka?
is …ing (polite)-고 있어요	끓고 있어요	[끌코 이써요]	kkeulko isseoyo

Past
Form	Korean	Sounds like	Romanized
polite-았/었어요	끓었어요	[끄러써요]	kkeureosseoyo
formal-았/었습니다	끓었습니다	[끄럳씀니다]	kkeureotseumnida
casual-았/었어	끓었어	[끄러써]	kkeureosseo
plain (written)-았/었다	끓었다	[끄럳따]	kkeureotda

Future
Form	Korean	Sounds like	Romanized
polite — will-(으)ㄹ 거예요	끓을 거예요	[끄를 꺼예요]	kkeureul geoyeyo
formal-(으)ㄹ 겁니다	끓을 겁니다	[끄를 껌니다]	kkeureul geomnida
casual-(으)ㄹ 거야	끓을 거야	[끄를 꺼야]	kkeureul geoya
formal — I will (intention)-겠습니다	끓겠습니다	[끌켇씀니다]	kkeulketseumnida

Negative
Form	Korean	Sounds like	Romanized
not (short)안 …	안 끓어요	[안 끄러요]	an kkeureoyo
did not안 …았/었어요	안 끓었어요	[안 끄러써요]	an kkeureosseoyo
not (long)-지 않아요	끓지 않아요	[끌치 아나요]	kkeulchi anayo
cannot못 …	못 끓어요	[몯 끄러요]	mot kkeureoyo

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	끓으세요	[끄르세요]	kkeureuseyo
honorific — past-(으)셨어요	끓으셨어요	[끄르셔써요]	kkeureusyeosseoyo
honorific — formal-(으)십니다	끓으십니다	[끄르심니다]	kkeureusimnida

Connecting
Form	Korean	Sounds like	Romanized
… and-고	끓고	[끌코]	kkeulko
… so / and then-아/어서	끓어서	[끄러서]	kkeureoseo
if …-(으)면	끓으면	[끄르면]	kkeureumyeon
… but-지만	끓지만	[끌치만]	kkeulchiman
because …-(으)니까	끓으니까	[끄르니까]	kkeureunikka
… and / but (background)-는데	끓는데	[끌른데]	kkeulleunde
even if …-아/어도	끓어도	[끄러도]	kkeureodo
while …-(으)면서	끓으면서	[끄르면서]	kkeureumyeonseo
before …-기 전에	끓기 전에	[끌키 저네]	kkeulki jeone
after …-(으)ㄴ 후에	끓은 후에	[끄른 후에]	kkeureun hue

Describing a noun
These go before a noun: “the food (that) I ate”, “a cold day”.
Form	Korean	Sounds like	Romanized
(that) … now-는	끓는	[끌른]	kkeulleun
(that) …ed-(으)ㄴ	끓은	[끄른]	kkeureun
(that) will …-(으)ㄹ	끓을	[끄를]	kkeureul

Useful patterns
Form	Korean	Sounds like	Romanized
I want to …-고 싶어요	끓고 싶어요	[끌코 시퍼요]	kkeulko sipeoyo
can …-(으)ㄹ 수 있어요	끓을 수 있어요	[끄를 쑤 이써요]	kkeureul su isseoyo
cannot …-(으)ㄹ 수 없어요	끓을 수 없어요	[끄를 쑤 업써요]	kkeureul su eopseoyo
have to …-아/어야 해요	끓어야 해요	[끄러야 해요]	kkeureoya haeyo
may … / it’s OK to …-아/어도 돼요	끓어도 돼요	[끄러도 돼요]	kkeureodo dwaeyo
must not …-(으)면 안 돼요	끓으면 안 돼요	[끄르면 안 돼요]	kkeureumyeon an dwaeyo
…ing (noun)-기	끓기	[끌키]	kkeulki

How 끓다 changes

끓 ends in a consonant, so 아/어 endings are added as they are → 끓어요, and endings written -(으) add 으 → 끓으면, 끓을. 끓다 is regular.

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

Questions

How do you say “boil” in Korean?

“To boil” is 끓다 (kkeulta), pronounced [끌타]. In a sentence: 물이 끓어요. — The water is boiling.

What is the past tense of 끓다?

끓었어요 (kkeureosseoyo) is the polite past tense of 끓다 (“to boil”). Formal: 끓었습니다; casual: 끓었어.

How do you say 끓다 politely?

Everyday polite: 끓어요 (kkeureoyo). Formal: 끓습니다. Casual, with close friends: 끓어.

Is 끓다 irregular?

No. 끓 ends in a consonant, so 아/어 endings are added as they are → 끓어요, and endings written -(으) add 으 → 끓으면, 끓을. 끓다 is regular.

More regular words like 끓다

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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