To think that / Surprise

This pattern is used to express surprise, disbelief, or a strong emotional reaction to a fact you've just learned. It's equivalent to saying "To think that...!" or "I can't believe...!" in English. It often forms a complete exclamatory sentence on its own.

Formation

The ending changes based on the word type.

Verbs & Adjectives: Attach -다니 directly to the stem.

가다 → 가다니 (To think that you're going!)

예쁘다 → 예쁘다니 (To think that it's pretty!)

합격하다 → 합격하다니 (To think that you passed!)

Nouns: Attach -(이)라니.

Nouns ending in a consonant + -이라니

월요일 → 월요일이라니 (To think it's Monday!)

품절 → 품절이라니 (To think it's sold out!)

Nouns ending in a vowel + -라니

공짜 → 공짜라니 (To think it's free!)

거짓말 → 거짓말이라니 (To think it's a lie!)

벌써 월요일이라니! / 네가 합격하다니! / 이렇게 맛있는 게 공짜라니! / 내 생일을 까먹다니!

The emotion conveyed by -다니 / -라니 depends entirely on the context and your tone of voice. It can express everything from delight to frustration.

Positive Surprise & Admiration

Use it to react to good news, amazing facts, or something pleasantly unexpected.

Context: Someone passed a difficult exam, or you received a wonderful gift.

Example: 네가 합격하다니! (To think that you passed! That's amazing!)

Negative Surprise & Disbelief

Use it to react to bad news, frustrating situations, or something you find hard to accept.

Context: You have to work overtime again, or you just found out the exam is tomorrow.

Example: 또 야근이라니! (I can't believe I have to work overtime again!)

Neutral Shock

Sometimes it's just pure shock without a strong positive or negative feeling.

Example: 벌써 12월이라니! (I can't believe it's already December!)

이렇게 맛있는 게 공짜라니! / 또 야근이라니! / 내일이 시험이라니! / BTS 콘서트 티켓이 매진이라니!

While -다니 / -라니 often stands alone as a complete exclamation, it's technically a shortened form of a longer sentence. Understanding this helps clarify its usage.

Standalone Exclamation

This is the most common usage. The rest of the thought (e.g., "...is unbelievable") is implied.

품절이라니... (Sold out... I can't believe it.)

With Adverbs of Surprise

It frequently appears with adverbs that heighten the sense of shock or disbelief.

벌써: 벌써 월요일이라니! (I can't believe it's already Monday!)

아니: 아니, 이게 10만 원이라니! (No way, to think this is 100,000 won!)

어떻게: 어떻게 내 생일을 까먹다니! (How could you forget my birthday!)

The Implied Full Sentence

The pattern is a contraction of -(ㄴ/는)다고 하니, which means "Hearing that..." or "Given that...". The full thought would be something like 네가 합격했다니 (정말) 놀랍다 (It's amazing to hear you passed).

벌써 12월이라니! / 또 야근이라니! / 우리가 헤어지다니, 말도 안 돼. / 로또가 된 게 꿈이라니!

This pattern can be easily adjusted for politeness by adding -요 at the end. The core meaning of surprise remains the same, but the delivery becomes more respectful.

Casual Form (반말)

Use -다니 or -(이)라니 with friends, family, or people younger than you.

내가 1등이라니! (I can't believe I'm in first place!)

내 생일을 까먹다니! (I can't believe you forgot my birthday!)

Polite Form (해요체)

Add -요 to make it -다니요 or -(이)라니요. Use this when speaking to elders, superiors, or in formal situations.

제가 1등이라니요! (I can't believe I'm in first place!)

제 생일을 까먹다니요! (I can't believe you forgot my birthday!)

벌써 아침이라니! / 벌써 아침이라니요! / 우리가 헤어지다니! / 우리가 헤어지다니요! / 이게 10만 원이라니! / 이게 10만 원이라니요!