🧾

High Probability: -(으)ㅁ에 틀림없다

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Advanced Grammar
🔮
TL;DR 🦄
  • 🔮 -(으)ㅁ에 틀림없다 means there is no doubt that... / it is certain that... / it must be the case that...
  • 📋 It is a formal, written-sounding certainty pattern built from -(으)ㅁ (turning a clause into a formal fact) + 에 틀림없다 (there is no mistake/doubt in it).
  • 🧠 Use it for evidence-based conclusions in reports, analysis, formal writing, academic-style claims, and polished explanations — not for casual “I guess.”
🔊
🎧 Iru Helper Note — Use
Korean Helper Widgets
Korean Helper Widgets to hear sentences like 그가 전문가임에 틀림없다 (There is no doubt that the person is an expert), 이미 검토했음에 틀림없다 (It is certain that someone already reviewed it), and 문제가 심각함에 틀림없다 (There is no doubt that the problem is serious). Listen for the formal certainty rhythm. 🔮
 

🌈 The Big Picture

-(으)ㅁ에 틀림없다 is advanced “no doubt” Korean. It packages a whole idea as a formal fact, then says there is no mistake in that conclusion.
 
It is closely related to -(으)ㄹ 게 틀림없다 (must be / is surely), but it sounds more written, analytical, and report-like.
 
Compare:
  • 그 사람은 의사일 게 틀림없어요. (That person must be a doctor.) 🩺
      • Polite spoken/written conclusion.
  • 그 사람이 의사임에 틀림없다. (There is no doubt that the person is a doctor.) 🩺
      • More formal, written, and fact-framing.
 
This grammar is useful when you want to sound like you are making a carefully supported conclusion:
  • 자료가 이미 공유되었음에 틀림없다. (There is no doubt that the materials were already shared.) 📂
  • 그 결정이 중요한 전환점임에 틀림없다. (There is no doubt that the decision is an important turning point.) 🧭
  • 상황이 예상보다 복잡함에 틀림없다. (There is no doubt that the situation is more complicated than expected.) 🧩

🎨 The Core -(으)ㅁ에 틀림없다 Family

1. Noun + 임에 틀림없다

Use this when you are certain about identity, category, or role.
  • 전문가임에 틀림없다 — there is no doubt that someone is an expert
  • 핵심 원인임에 틀림없다 — there is no doubt that it is the main cause
  • 중요한 변화임에 틀림없다 — there is no doubt that it is an important change
 

2. Adjective/descriptive verb stem + -(으)ㅁ에 틀림없다

Use this when you are certain about a state or quality.
  • 중요하다 → 중요함에 틀림없다 — there is no doubt that it is important
  • 심각하다 → 심각함에 틀림없다 — there is no doubt that it is serious
  • 어렵다 → 어려움에 틀림없다 — there is no doubt that it is difficult
 

3. Verb stem + -(으)ㅁ에 틀림없다

Use this when you are certain that an action or state is true as a fact.
  • 알고 있다 → 알고 있음에 틀림없다 — there is no doubt that someone knows / is aware
  • 진행되다 → 진행됨에 틀림없다 — there is no doubt that it is being carried out
  • 영향을 미치다 → 영향을 미침에 틀림없다 — there is no doubt that it affects something
 

4. Past fact + -았/었음에 틀림없다

Use this when you are certain something already happened.
  • 검토했다 → 검토했음에 틀림없다 — there is no doubt that someone reviewed it
  • 변경되었다 → 변경되었음에 틀림없다 — there is no doubt that it was changed
  • 완료되었다 → 완료되었음에 틀림없다 — there is no doubt that it was completed
 

5. Future or prediction: -(으)ㄹ 것임에 틀림없다

For future predictions, advanced formal Korean often uses -(으)ㄹ 것임에 틀림없다, because the predicted event is packaged as “the fact that it will happen.”
  • 증가할 것임에 틀림없다 — there is no doubt that it will increase
  • 영향을 줄 것임에 틀림없다 — there is no doubt that it will have an effect
  • 논의될 것임에 틀림없다 — there is no doubt that it will be discussed

🛠️ How They Work in a Sentence

1. Formal identity conclusion
  • 그 자료의 작성자는 내부 담당자임에 틀림없다.
      • The author of the material is undoubtedly an internal person in charge. 📄
      작성자 = author/writer; 내부 담당자 = internal person in charge.
 
2. Evidence-based state conclusion
  • 반응이 빠른 것을 보면 수요가 높음에 틀림없다.
      • Judging from the quick response, there is no doubt that demand is high. 📈
      반응 = response; 수요 = demand; 높다 = to be high.
 
3. Past formal conclusion
  • 회의록에 기록된 것을 보면 이미 논의되었음에 틀림없다.
      • Judging from what is recorded in the meeting minutes, there is no doubt that it was already discussed. 📝
      회의록 = meeting minutes; 기록되다 = to be recorded; 논의되다 = to be discussed.

🧩 General Formation Rule

Noun + 임에 틀림없다

  • 전문가 → 전문가임에 틀림없다 (there is no doubt that someone is an expert)
  • 원인 → 원인임에 틀림없다 (there is no doubt that it is the cause)
  • 사실 → 사실임에 틀림없다 (there is no doubt that it is true / a fact)
 

Vowel-ending stem + -ㅁ에 틀림없다

  • 크다 → 큼에 틀림없다 (there is no doubt that it is big/significant)
  • 바쁘다 → 바쁨에 틀림없다 (there is no doubt that someone is busy)
  • 미치다 → 미침에 틀림없다 (there is no doubt that something affects something, as in 영향을 미침)
 

Consonant-ending stem + -음에 틀림없다

  • 높다 → 높음에 틀림없다 (there is no doubt that it is high)
  • 있다 → 있음에 틀림없다 (there is no doubt that there is / someone has)
  • 없다 → 없음에 틀림없다 (there is no doubt that there is not / someone lacks)
 

ㄹ-ending stem + -ㅁ에 틀림없다

The spelling compresses.
  • 알다 → 앎에 틀림없다 (there is no doubt that someone knows)
  • 만들다 → 만듦에 틀림없다 (there is no doubt that someone makes/made it)
  • 늘다 → 늚에 틀림없다 (there is no doubt that something increases/improves)
 

Past + -았/었음에 틀림없다

  • 확인했다 → 확인했음에 틀림없다 (there is no doubt that someone checked/confirmed)
  • 도착했다 → 도착했음에 틀림없다 (there is no doubt that someone arrived)
  • 변경되었다 → 변경되었음에 틀림없다 (there is no doubt that it was changed)
 

Future/prediction + -(으)ㄹ 것임에 틀림없다

  • 증가하다 → 증가할 것임에 틀림없다 (there is no doubt that it will increase)
  • 확대되다 → 확대될 것임에 틀림없다 (there is no doubt that it will expand)
  • 문제가 되다 → 문제가 될 것임에 틀림없다 (there is no doubt that it will become a problem)

📚 Cross-check note

The component forms were cross-checked against korean.go.kr: 틀림없다 is used for certainty/no doubt, and -(으)ㅁ creates formal noun-like facts such as 있음, 없음, and 임. This lesson treats -(으)ㅁ에 틀림없다 as a formal certainty pattern built from those parts. ✅

🪞 Synonym Alert

  • -(으)ㅁ에 틀림없다 — formal/written “there is no doubt that...” 📋
  • -(으)ㄹ 게 틀림없다 — more common “must be / is surely...” 🔮
  • 분명하다 — to be clear/certain; often used as 분명하다 or 분명히 🔎
  • 확실하다 — to be certain/sure; slightly broader and very common ✅
  • -(으)ㄹ 리가 없다 — strong negative certainty: “there is no way...” 🚫
 
Quick contrast:
  • 그가 전문가일 게 틀림없다. (He/They must be an expert.) More prediction-like.
  • 그가 전문가임에 틀림없다. (There is no doubt that he/they are an expert.) More fact-framed and formal.
  • 그가 전문가일 리가 없다. (There is no way he/they are an expert.) Strong negative certainty.

⚠️ Pitfalls to Dodge

  • ❌ 전문가에 틀림없다 → ✅ 전문가임에 틀림없다 (For noun identity in this pattern, use 임에.)
  • ❌ 중요하다에 틀림없다 → ✅ 중요함에 틀림없다 (Turn the adjective into a formal fact.)
  • ❌ 변경되었는 것에 틀림없다 → ✅ 변경되었음에 틀림없다 (Use the formal -음 shape.)
  • ❌ Treating it as obligation “must” → ✅ This is certainty, not requirement. For obligation, use -아/어야 하다.
  • ❌ Using it casually in every conversation → ✅ Prefer -(으)ㄹ 것 같아요, 확실해요, or -(으)ㄹ 게 틀림없어요 in ordinary speech.
 
🔮 Bottom line: -(으)ㅁ에 틀림없다 is the formal “no doubt” stamp. It turns a conclusion into a polished fact: identity, state, past event, or future prediction — then marks it as certain. 📋✨
 

Try this exercise

Instructions: Complete each sentence with the formal certainty form. Decide whether the base is a noun, state, past fact, or future prediction, then check the Answer toggle.
1. 전문가 → 그 사람은 이 분야의 ＿＿＿＿ 틀림없다.
There is no doubt that the person is an expert in this field. 🧑‍💼
Answer
전문가임에 — noun identity uses N임에 틀림없다.
2. 중요하다 → 이 결정은 매우 ＿＿＿＿ 틀림없다.
There is no doubt that this decision is very important. 🧭
Answer
중요함에 — 중요하다 becomes 중요함.
3. 높다 → 현재 수요가 ＿＿＿＿ 틀림없다.
There is no doubt that current demand is high. 📈
Answer
높음에.
4. 알고 있다 → 담당자는 이미 상황을 ＿＿＿＿ 틀림없다.
There is no doubt that the person in charge already knows the situation. 🧠
Answer
알고 있음에.
5. 검토했다 → 자료는 이미 ＿＿＿＿ 틀림없다.
There is no doubt that the materials were already reviewed. 📂
Answer
검토했음에 — past fact + 음에 틀림없다.
6. 변경되었다 → 일정이 ＿＿＿＿ 틀림없다.
There is no doubt that the schedule was changed. 📅
Answer
변경되었음에.
7. 증가하다 → 비용은 앞으로 ＿＿＿＿ 틀림없다.
There is no doubt that costs will increase going forward. 💸
Answer
증가할 것임에 — future prediction uses -(으)ㄹ 것임에 틀림없다.
8. 원인 → 그것이 핵심 ＿＿＿＿ 틀림없다.
There is no doubt that it is the main cause. 🧩
Answer
원인임에.
9. Fix: ❌ 심각하다에 틀림없다
There is no doubt that it is serious. 🚨
Answer
심각함에 틀림없다.
10. Choose the formal written form: 의사일 게 틀림없다 / 의사임에 틀림없다
There is no doubt that the person is a doctor. 🩺
Answer
의사임에 틀림없다 — more formal and fact-framed.
📚
Vocabulary Box
  • 전문가 → expert
  • 분야 → field
  • 결정 → decision
  • 중요하다 → to be important
  • 수요 → demand
  • 높다 → to be high
  • 담당자 → person in charge
  • 상황 → situation
  • 검토하다 → to review
  • 변경되다 → to be changed
  • 증가하다 → to increase
  • 원인 → cause
  • 심각하다 → to be serious
Tip 💡 If the sentence sounds like a report conclusion, -(으)ㅁ에 틀림없다 may be exactly the suit-and-tie grammar you want.
🚀
Want more reps? The Practice Hub below trains identity, states, past facts, future predictions, and formal-vs-casual certainty choices. 🔮
 
📦
🎯 Practice Hub — High Probability: -(으)ㅁ에 틀림없다
 
Welcome to the formal certainty lab. 🔮 You’ll practice turning evidence into polished conclusions: who someone is, what state something is in, what happened already, and what will almost certainly happen next.
 
🔊 Audio reminder: Use
Korean Helper Widgets
Korean Helper Widgets when you want to hear a completed sentence aloud.
 
📝 Instructions: Complete each formal conclusion, then open the Answer toggle. Ask yourself: “Am I packaging this as a formal fact?”
 

Exercise 1 — Identity Conclusions: N임에 틀림없다 🪪

A. 그 사람은 이 분야의 전문가＿＿＿＿ 틀림없다.
There is no doubt that the person is an expert in this field. 🧑‍💼
Answer
임에 — noun identity uses N임에 틀림없다.
B. 그 자료는 내부 문서＿＿＿＿ 틀림없다.
There is no doubt that the material is an internal document. 📄
Answer
임에.
C. 이 변화는 중요한 전환점＿＿＿＿ 틀림없다.
There is no doubt that this change is an important turning point. 🧭
Answer
임에.
D. 그 발언은 공식 입장＿＿＿＿ 틀림없다.
There is no doubt that the remark is an official position. 🏛️
Answer
임에.
E. 그것이 핵심 원인＿＿＿＿ 틀림없다.
There is no doubt that it is the main cause. 🧩
Answer
임에.
F. 이번 결과는 의미 있는 성과＿＿＿＿ 틀림없다.
There is no doubt that this result is a meaningful achievement. 🏆
Answer
임에.
G. 그 선택은 전략적 판단＿＿＿＿ 틀림없다.
There is no doubt that the choice is a strategic judgment. ♟️
Answer
임에.
H. 이 수치는 중요한 근거＿＿＿＿ 틀림없다.
There is no doubt that this figure is important evidence. 📊
Answer
임에.
I. 그 요청은 긴급 사안＿＿＿＿ 틀림없다.
There is no doubt that the request is an urgent matter. 🚨
Answer
임에.
J. 이 문장은 잘못된 표현＿＿＿＿ 틀림없다.
There is no doubt that this sentence is an incorrect expression. ✍️
Answer
임에.
🪪
Identity Vocabulary
  • 전문가 → expert
  • 내부 문서 → internal document
  • 전환점 → turning point
  • 공식 입장 → official position
  • 핵심 원인 → main cause
  • 성과 → achievement
  • 전략적 판단 → strategic judgment
  • 근거 → evidence / basis
  • 긴급 사안 → urgent matter
  • 잘못된 표현 → incorrect expression
Tip 💡 Noun + 임에 틀림없다 is the cleanest form for formal identity conclusions.
 

Exercise 2 — States and Qualities: -(으)ㅁ에 틀림없다 📋

A. 이 문제는 매우 중요＿＿＿＿ 틀림없다.
There is no doubt that this issue is very important. 📌
Answer
중요함에 — 중요하다 becomes 중요함.
B. 현재 상황은 상당히 심각＿＿＿＿ 틀림없다.
There is no doubt that the current situation is quite serious. 🚨
Answer
심각함에.
C. 이 기준은 너무 엄격＿＿＿＿ 틀림없다.
There is no doubt that this standard is too strict. 📏
Answer
엄격함에.
D. 그 절차는 복잡＿＿＿＿ 틀림없다.
There is no doubt that the procedure is complicated. 🧩
Answer
복잡함에.
E. 수요는 예상보다 높＿＿＿＿ 틀림없다.
There is no doubt that demand is higher than expected. 📈
Answer
높음에.
F. 그 설명은 다소 어렵＿＿＿＿ 틀림없다.
There is no doubt that the explanation is somewhat difficult. 📚
Answer
어려움에 — 어렵다 is ㅂ-irregular: 어려움.
G. 그 자료는 실제와 다르＿＿＿＿ 틀림없다.
There is no doubt that the material differs from reality. 🔍
Answer
다름에 — 다르다 becomes 다름.
H. 새로운 방식은 효과가 있＿＿＿＿ 틀림없다.
There is no doubt that the new method is effective. 🛠️
Answer
있음에.
I. 그 주장에는 근거가 없＿＿＿＿ 틀림없다.
There is no doubt that the claim lacks evidence. 🧾
Answer
없음에.
J. 이번 변화는 영향이 크＿＿＿＿ 틀림없다.
There is no doubt that this change has a significant impact. 🌊
Answer
큼에 — 크다 becomes 큼.
📋
State Vocabulary
  • 중요하다 → to be important
  • 심각하다 → to be serious
  • 엄격하다 → to be strict
  • 복잡하다 → to be complicated
  • 높다 → to be high
  • 어렵다 → to be difficult
  • 다르다 → to be different
  • 있다 → to exist / to have
  • 없다 → to not exist / to lack
  • 크다 → to be big/significant
Tip 💡 Descriptive verbs become formal fact nouns before 에 틀림없다.
 

Exercise 3 — Past Evidence: -았/었음에 틀림없다 🕰️

A. 자료는 이미 검토＿＿＿＿ 틀림없다.
There is no doubt that the materials were already reviewed. 📂
Answer
검토했음에.
B. 일정은 어제 변경＿＿＿＿ 틀림없다.
There is no doubt that the schedule was changed yesterday. 📅
Answer
변경되었음에.
C. 신청은 정상적으로 접수＿＿＿＿ 틀림없다.
There is no doubt that the application was received normally. 📬
Answer
접수되었음에.
D. 문제는 회의에서 논의＿＿＿＿ 틀림없다.
There is no doubt that the issue was discussed in the meeting. 📝
Answer
논의되었음에.
E. 결과는 보고서에 기록＿＿＿＿ 틀림없다.
There is no doubt that the result was recorded in the report. 📊
Answer
기록되었음에.
F. 담당자는 그 사실을 이미 확인＿＿＿＿ 틀림없다.
There is no doubt that the person in charge already confirmed the fact. ✅
Answer
확인했음에.
G. 회의는 예정대로 진행＿＿＿＿ 틀림없다.
There is no doubt that the meeting proceeded as scheduled. 🗓️
Answer
진행되었음에.
H. 안내문은 이미 공유＿＿＿＿ 틀림없다.
There is no doubt that the notice was already shared. 📢
Answer
공유되었음에.
I. 절차는 모두 완료＿＿＿＿ 틀림없다.
There is no doubt that all procedures were completed. 🧾
Answer
완료되었음에.
J. 그 의견은 충분히 반영＿＿＿＿ 틀림없다.
There is no doubt that the opinion was sufficiently reflected. 🪞
Answer
반영되었음에.
🕰️
Past Evidence Vocabulary
  • 검토하다 → to review
  • 변경되다 → to be changed
  • 접수되다 → to be received/registered
  • 논의되다 → to be discussed
  • 기록되다 → to be recorded
  • 확인하다 → to confirm
  • 진행되다 → to proceed
  • 공유되다 → to be shared
  • 완료되다 → to be completed
  • 반영되다 → to be reflected
Tip 💡 Past fact + certainty = -았/었음에 틀림없다.
 

Exercise 4 — Future Predictions: -(으)ㄹ 것임에 틀림없다 🔮

A. 비용은 앞으로 증가＿＿＿＿ 틀림없다.
There is no doubt that costs will increase going forward. 💸
Answer
증가할 것임에 — future prediction uses -(으)ㄹ 것임에 틀림없다.
B. 논의는 다음 회의에서 계속＿＿＿＿ 틀림없다.
There is no doubt that the discussion will continue at the next meeting. 📝
Answer
계속될 것임에.
C. 이번 결정은 큰 영향을 미치＿＿＿＿ 틀림없다.
There is no doubt that this decision will have a major impact. 🌊
Answer
미칠 것임에.
D. 새 제도는 곧 확대＿＿＿＿ 틀림없다.
There is no doubt that the new system will soon expand. 🏗️
Answer
확대될 것임에.
E. 그 자료는 분석에 도움을 주＿＿＿＿ 틀림없다.
There is no doubt that the material will help the analysis. 🔍
Answer
줄 것임에.
F. 이 문제는 다시 제기＿＿＿＿ 틀림없다.
There is no doubt that this issue will be raised again. 🙋
Answer
제기될 것임에.
G. 수요는 계속 늘＿＿＿＿ 틀림없다.
There is no doubt that demand will keep increasing. 📈
Answer
늘 것임에 — ㄹ stem 늘다 keeps ㄹ before 것.
H. 그 변화는 중요한 문제가 되＿＿＿＿ 틀림없다.
There is no doubt that the change will become an important issue. ⚠️
Answer
될 것임에.
I. 그 결정은 긍정적인 평가를 받＿＿＿＿ 틀림없다.
There is no doubt that the decision will receive a positive evaluation. 🌟
Answer
받을 것임에.
J. 이 기준은 앞으로 더 엄격해지＿＿＿＿ 틀림없다.
There is no doubt that this standard will become stricter going forward. 📏
Answer
엄격해질 것임에.
🔮
Prediction Vocabulary
  • 증가하다 → to increase
  • 계속되다 → to continue
  • 영향을 미치다 → to affect / have an impact
  • 확대되다 → to expand
  • 도움을 주다 → to help
  • 제기되다 → to be raised
  • 늘다 → to increase
  • 문제가 되다 → to become a problem/issue
  • 평가를 받다 → to receive an evaluation
  • 엄격해지다 → to become stricter
Tip 💡 For future formal certainty, package the prediction as -(으)ㄹ 것임.
 

Exercise 5 — Mixed Mastery + Pitfall Patrol 🛡️

A. Fix: ❌ 전문가에 틀림없다
There is no doubt that someone is an expert. 🧑‍💼
Answer
✅ 전문가임에 틀림없다 — noun identity needs 임에.
B. Fix: ❌ 중요하다에 틀림없다
There is no doubt that it is important. 📌
Answer
✅ 중요함에 틀림없다.
C. Fix: ❌ 변경되었는 것에 틀림없다
There is no doubt that it was changed. 📅
Answer
✅ 변경되었음에 틀림없다.
D. Choose the formal fact-framed sentence.
① 그가 전문가일 게 틀림없다.
② 그가 전문가임에 틀림없다.
Answer
② 그가 전문가임에 틀림없다 — more formal and identity-focused.
E. Choose the ordinary strong-probability sentence.
① 비가 올 게 틀림없다.
② 비가 옴에 틀림없다.
Answer
① 비가 올 게 틀림없다 — more natural for a weather prediction.
F. Translate: “There is no doubt that this is the main cause.” 🧩
Answer
이것이 핵심 원인임에 틀림없다.
G. Translate: “There is no doubt that the situation is serious.” 🚨
Answer
상황이 심각함에 틀림없다.
H. Translate: “There is no doubt that the issue was discussed.” 📝
Answer
문제가 논의되었음에 틀림없다.
I. Translate: “There is no doubt that demand will increase.” 📈
Answer
수요가 증가할 것임에 틀림없다.
J. Choose the strong negative certainty.
① 그가 전문가임에 틀림없다.
② 그가 전문가일 리가 없다.
Answer
② 그가 전문가일 리가 없다 — “There is no way that person is an expert.”
🛡️
Final Check
  • 전문가 → 전문가임에 틀림없다
  • 중요하다 → 중요함에 틀림없다
  • 높다 → 높음에 틀림없다
  • 어렵다 → 어려움에 틀림없다
  • 검토했다 → 검토했음에 틀림없다
  • 증가하다 → 증가할 것임에 틀림없다
  • -(으)ㄹ 게 틀림없다 → common strong probability
  • -(으)ㄹ 리가 없다 → strong negative certainty
Tip 💡 The formal pattern is a three-step machine: make a fact with -(으)ㅁ, add 에, then stamp it with 틀림없다.
 
🎉 Practice complete. You can now use -(으)ㅁ에 틀림없다 to write polished, evidence-backed certainty: 전문가임에 틀림없다, 중요함에 틀림없다, 검토했음에 틀림없다, and 증가할 것임에 틀림없다. Formal confidence unlocked. 🔮📋