시다 conjugation

to be sour · sida · sounds like [시다]

Short answer: “Sour” in Korean is 시다 (sida). Polite present: 셔요 (syeoyo); past: 셨어요 (syeosseoyo); future: 실 거예요. It is regular.

Present셔요[셔요] · syeoyo
Past셨어요[셔써요] · syeosseoyo
Future실 거예요[실 꺼예요] · sil geoyeyo
Negative안 셔요[안 셔요] · an syeoyo

시다 in sentences

레몬은 셔요.Lemons are sour.
저는 신 음식을 못 먹어요.I can’t eat sour food.

All forms of 시다

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	셔요	[셔요]	syeoyo
formal-(스)ㅂ니다	십니다	[심니다]	simnida
casual-아/어	셔	[셔]	syeo
plain (written)-다	시다	[시다]	sida
formal question-(스)ㅂ니까?	십니까?	[심니까]	simnikka?

Past
Form	Korean	Sounds like	Romanized
polite-았/었어요	셨어요	[셔써요]	syeosseoyo
formal-았/었습니다	셨습니다	[셛씀니다]	syeotseumnida
casual-았/었어	셨어	[셔써]	syeosseo
plain (written)-았/었다	셨다	[셛따]	syeotda

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

Negative
Form	Korean	Sounds like	Romanized
not (short)안 …	안 셔요	[안 셔요]	an syeoyo
did not안 …았/었어요	안 셨어요	[안 셔써요]	an syeosseoyo
not (long)-지 않아요	시지 않아요	[시지 아나요]	siji 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	시세요	[시세요]	siseyo
honorific — past-(으)셨어요	시셨어요	[시셔써요]	sisyeosseoyo
honorific — formal-(으)십니다	시십니다	[시심니다]	sisimnida

Connecting
Form	Korean	Sounds like	Romanized
… and-고	시고	[시고]	sigo
… so / and then-아/어서	셔서	[셔서]	syeoseo
if …-(으)면	시면	[시면]	simyeon
… but-지만	시지만	[시지만]	sijiman
because …-(으)니까	시니까	[시니까]	sinikka
… and / but (background)-(으)ㄴ데	신데	[신데]	sinde
even if …-아/어도	셔도	[셔도]	syeodo
while …-(으)면서	시면서	[시면서]	simyeonseo

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	신	[신]	sin
(that) will …-(으)ㄹ	실	[실]	sil

Useful patterns
Form	Korean	Sounds like	Romanized
can be …-(으)ㄹ 수 있어요	실 수 있어요	[실 쑤 이써요]	sil su isseoyo
cannot be …-(으)ㄹ 수 없어요	실 수 없어요	[실 쑤 업써요]	sil su eopseoyo
have to be …-아/어야 해요	셔야 해요	[셔야 해요]	syeoya haeyo
it’s OK if it’s …-아/어도 돼요	셔도 돼요	[셔도 돼요]	syeodo dwaeyo
…ly (adverb)-게	시게	[시게]	sige
becomes …-아/어지다	셔져요	[셔저요]	syeojeoyo
…ing (noun)-기	시기	[시기]	sigi

How 시다 changes

시 ends in a vowel, so 시 + 아/어 becomes 셔 → 셔요, 셨어요. Endings written -(으) attach directly → 시면, 실. 시다 is regular.

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

Questions

How do you say “sour” in Korean?

“Sour” is 시다 (sida), pronounced [시다]. In a sentence: 레몬은 셔요. — Lemons are sour.

What is the past tense of 시다?

셨어요 (syeosseoyo) is the polite past tense of 시다 (“to be sour”). Formal: 셨습니다; casual: 셨어.

How do you say 시다 politely?

Everyday polite: 셔요 (syeoyo). Formal: 십니다. Casual, with close friends: 셔.

How do you say “not sour” in Korean?

안 셔요 or 시지 않아요. Both mean the same; the first is more common in speech.

Is 시다 irregular?

No. 시 ends in a vowel, so 시 + 아/어 becomes 셔 → 셔요, 셨어요. Endings written -(으) attach directly → 시면, 실. 시다 is regular.

More regular words like 시다

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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