꼭 (kkok) · 반드시 (ban-deu-si, bandeusi) · 틀림없이 (teul-rim-eop-i, teulrimeopi)
꼭 (kkok), 반드시 (bandeusi), and 틀림없이 (teullimeopsi) all express strong certainty, but 꼭 stresses obligation or necessity, 반드시 emphasizes high necessity or duty, and 틀림없이 highlights certainty of facts or outcomes.
One lane per word — no nested boxes, just the gist.
Used to emphasize something essential or that must be done.
When to use
keeping promises, essential actions, strong encouragement
The nuance
꼭 is mainly used for obligations, promises, or necessities that must be fulfilled, expressing strong will or encouragement.
Used to emphasize that something absolutely must happen or cannot be omitted.
When to use
legal obligation, official instructions, strict conditions
The nuance
반드시 is more formal and indicates stronger necessity or obligation than 꼭, often used in legal, official, or strict contexts.
Used to state facts or outcomes that are certain beyond doubt.
When to use
certain facts, future predictions, confirmed outcomes
The nuance
틀림없이 emphasizes certainty of results or facts, suitable for future predictions, sure judgments, or confirmed facts.
내일 꼭 와야 해.
nae-il kkok wa-ya hae., nae il kkok wa ya hae.
꼭 fits for promises or essential actions.
내일 반드시 와야 해.
nae-il ban-deu-si wa-ya hae., nae il ban deu si wa ya hae.
반드시 indicates stronger obligation, suitable for formal contexts.
내일 틀림없이 와야 해.
nae-il teul-rim-eop-i wa-ya hae., nae il teul rim eop i wa ya hae.
틀림없이 is for certainty of facts/results, not obligations.
이 문제는 반드시 해결해야 한다.
i mun-je-neun ban-deu-si hae-gyeol-hae-ya han-da., i mun je neun ban deu si hae gyeol hae ya han da.
반드시 fits strong necessity in official statements.
이 문제는 꼭 해결해야 한다.
i mun-je-neun kkok hae-gyeol-hae-ya han-da., i mun je neun kkok hae gyeol hae ya han da.
꼭 expresses strong necessity but is less formal than 반드시.
이 문제는 틀림없이 해결해야 한다.
i mun-je-neun teul-rim-eop-i hae-gyeol-hae-ya han-da., i mun je neun teul rim eop i hae gyeol hae ya han da.
틀림없이 is used for certainty of results, not obligations.
그는 틀림없이 올 것이다.
geu-neun teul-rim-eop-i ol geos-i-da., geu neun teul rim eop i ol geos i da.
틀림없이 suits certain future predictions.
그는 반드시 올 것이다.
geu-neun ban-deu-si ol geos-i-da., geu neun ban deu si ol geos i da.
반드시 is better for obligations than future predictions.
When can you use “꼭”?
Which sentence fits best with “반드시”?
When is it NOT appropriate to use “틀림없이”?
