Adjectives · 하다 word

똑똑하다 conjugation

to be smart · ttokttokada · sounds like [똑또카다]

Short answer: “Smart” in Korean is 똑똑하다 (ttokttokada). Polite present: 똑똑해요 (ttokttokaeyo); past: 똑똑했어요 (ttokttokaesseoyo); future: 똑똑할 거예요. It is a 하다 adjective: 하 + 아/어 always becomes 해.

Present똑똑해요[똑또캐요] · ttokttokaeyo
Past똑똑했어요[똑또캐써요] · ttokttokaesseoyo
Future똑똑할 거예요[똑또칼 꺼예요] · ttokttokal geoyeyo
Negative안 똑똑해요[안 똑또캐요] · an ttokttokaeyo

똑똑하다 in sentences

그 학생은 정말 똑똑해요.That student is really smart.
똑똑한 강아지예요.It’s a smart dog.

All forms of 똑똑하다

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	똑똑해요	[똑또캐요]	ttokttokaeyo
formal-(스)ㅂ니다	똑똑합니다	[똑또캄니다]	ttokttokamnida
casual-아/어	똑똑해	[똑또캐]	ttokttokae
plain (written)-다	똑똑하다	[똑또카다]	ttokttokada
formal question-(스)ㅂ니까?	똑똑합니까?	[똑또캄니까]	ttokttokamnikka?

Past
Form	Korean	Sounds like	Romanized
polite-았/었어요	똑똑했어요	[똑또캐써요]	ttokttokaesseoyo
formal-았/었습니다	똑똑했습니다	[똑또캗씀니다]	ttokttokaetseumnida
casual-았/었어	똑똑했어	[똑또캐써]	ttokttokaesseo
plain (written)-았/었다	똑똑했다	[똑또캗따]	ttokttokaetda

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

Negative
Form	Korean	Sounds like	Romanized
not (short)안 …	안 똑똑해요	[안 똑또캐요]	an ttokttokaeyo
did not안 …았/었어요	안 똑똑했어요	[안 똑또캐써요]	an ttokttokaesseoyo
not (long)-지 않아요	똑똑하지 않아요	[똑또카지 아나요]	ttokttokaji 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	똑똑하세요	[똑또카세요]	ttokttokaseyo
honorific — past-(으)셨어요	똑똑하셨어요	[똑또카셔써요]	ttokttokasyeosseoyo
honorific — formal-(으)십니다	똑똑하십니다	[똑또카심니다]	ttokttokasimnida

Connecting
Form	Korean	Sounds like	Romanized
… and-고	똑똑하고	[똑또카고]	ttokttokago
… so / and then-아/어서	똑똑해서	[똑또캐서]	ttokttokaeseo
if …-(으)면	똑똑하면	[똑또카면]	ttokttokamyeon
… but-지만	똑똑하지만	[똑또카지만]	ttokttokajiman
because …-(으)니까	똑똑하니까	[똑또카니까]	ttokttokanikka
… and / but (background)-(으)ㄴ데	똑똑한데	[똑또칸데]	ttokttokande
even if …-아/어도	똑똑해도	[똑또캐도]	ttokttokaedo
while …-(으)면서	똑똑하면서	[똑또카면서]	ttokttokamyeonseo

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	똑똑한	[똑또칸]	ttokttokan
(that) will …-(으)ㄹ	똑똑할	[똑또칼]	ttokttokal

Useful patterns
Form	Korean	Sounds like	Romanized
can be …-(으)ㄹ 수 있어요	똑똑할 수 있어요	[똑또칼 쑤 이써요]	ttokttokal su isseoyo
cannot be …-(으)ㄹ 수 없어요	똑똑할 수 없어요	[똑또칼 쑤 업써요]	ttokttokal su eopseoyo
have to be …-아/어야 해요	똑똑해야 해요	[똑또캐야 해요]	ttokttokaeya haeyo
it’s OK if it’s …-아/어도 돼요	똑똑해도 돼요	[똑또캐도 돼요]	ttokttokaedo dwaeyo
…ly (adverb)-게	똑똑하게	[똑또카게]	ttokttokage
becomes …-아/어지다	똑똑해져요	[똑또캐저요]	ttokttokaejeoyo
…ing (noun)-기	똑똑하기	[똑또카기]	ttokttokagi

How 똑똑하다 changes

Every 하다 word works the same way: 하 + 여 becomes 해 → 똑똑해요, 똑똑했어요. With other endings 하 stays as it is: 똑똑합니다, 똑똑하면.

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

Questions

How do you say “smart” in Korean?

“Smart” is 똑똑하다 (ttokttokada), pronounced [똑또카다]. In a sentence: 그 학생은 정말 똑똑해요. — That student is really smart.

What is the past tense of 똑똑하다?

똑똑했어요 (ttokttokaesseoyo) is the polite past tense of 똑똑하다 (“to be smart”). Formal: 똑똑했습니다; casual: 똑똑했어.

How do you say 똑똑하다 politely?

Everyday polite: 똑똑해요 (ttokttokaeyo). Formal: 똑똑합니다. Casual, with close friends: 똑똑해.

How do you say “not smart” in Korean?

안 똑똑해요 or 똑똑하지 않아요. Both mean the same; the first is more common in speech.

Is 똑똑하다 irregular?

No. Every 하다 word works the same way: 하 + 여 becomes 해 → 똑똑해요, 똑똑했어요. With other endings 하 stays as it is: 똑똑합니다, 똑똑하면.

More 하다 words like 똑똑하다

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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