Expressing Certainty vs. Uncertainty

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Expressing Certainty vs. Uncertainty

Say exactly how sure you are — and sound more natural doing it.

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Iru Helper Note

Korean has a rich system for expressing degrees of certainty. Knowing which expression matches your actual confidence level is the difference between sounding fluent and sounding robotic.

확실하지는 않은데, 아마 맞는 것 같아요.

(I'm not certain, but it's probably right.)

🎯 What You'll Learn Today

When you speak Korean, you often need to signal not just what you think, but how sure you are. Korean offers a spectrum of expressions from total certainty (확실해요) to total uncertainty (잘 모르겠어요), with natural-sounding hedges in between. Using the right one makes your Korean sound precise, honest, and socially aware — especially important in Korean culture where overconfidence can seem rude.

📌 The Certainty Spectrum

Expression	Level	Meaning
확실해요 / 확실히	Very certain	I'm sure / definitely
맞아요 / 맞는 것 같아요	Certain / fairly certain	That's right / seems right
아마 / 아마도	Probably	Probably / I'd guess
-것 같아요	Uncertain impression	It seems like / I think
잘 모르겠어요	Uncertain	I'm not sure
모르겠어요	Uncertain / confused	I don't know / can't say
전혀 모르겠어요	Very uncertain	I have no idea at all

💡 Key pattern: Certainty → Direct statement. Uncertainty → 아마 + -것 같아요 or 잘 모르겠어요. Don't use 확실해요 unless you're genuinely certain — it's a strong claim.

Natural combinations:

Combination	Meaning
아마 맞는 것 같아요	It's probably right
확실하지는 않은데	I'm not certain, but...
잘 모르겠는데, 아마...	I'm not sure, but probably...
그럴 것 같기도 하고...	It might be that way, kind of...
확실히 말하기 어려워요	It's hard to say for certain

💬 Conversations in Action

Conversation 1 — Giving directions with uncertainty

A: 저기 카페가 어디 있는지 알아요? (Do you know where that café is?)

B: 잘 모르겠는데, 아마 저 골목 쪽인 것 같아요. 확실하진 않아요. (I'm not sure, but it's probably down that alley. I'm not certain.)

Conversation 2 — Answering a factual question

A: 내일 회의가 세 시죠? (The meeting tomorrow is at 3, right?)

B: 네, 확실해요. 캘린더에서 확인했어요. (Yes, I'm sure. I checked the calendar.)

🌏 Cultural Note — 겸손과 정확함 (Humility and Precision)

In Korean culture, admitting uncertainty is not a weakness — it's a sign of honesty and 겸손함 (humility). Saying 잘 모르겠어요 or 확실하지 않은데... is far more respected than guessing and being wrong. In workplace settings especially, Koreans prefer to say 확인하고 말씀드릴게요 (I'll check and let you know) rather than stating something uncertain as fact. Getting the certainty level right is a key part of being trusted as a communicator.

<summary>Try This Speaking Exercise

Choose the expression that best matches how sure you actually are.

A. You're 100% sure the train leaves at 7pm because you have the ticket in your hand.

<summary>Answer

확실해요, 일곱 시에 출발해요. 표가 있어요. (I'm certain — it departs at 7. I have the ticket.)

</summary>

B. Someone asks if a restaurant is good. You think it is but haven't been recently.

<summary>Answer

아마 맛있을 것 같아요. 전에 갔을 때 좋았어요. (It's probably good. It was nice when I went before.)

</summary>

C. Someone asks what the capital of Australia is. You think it's Sydney but aren't sure.

<summary>Answer

잘 모르겠는데, 아마 시드니인 것 같아요. 확실하지 않아요. (I'm not sure — it might be Sydney. I'm not certain.)

</summary>

D. Someone asks you something you genuinely have no idea about.

<summary>Answer

전혀 모르겠어요. (I have no idea at all.)

</summary>

E. You're fairly sure a meeting is tomorrow but want to signal you haven't double-checked.

<summary>Answer

아마 내일인 것 같은데, 확인해볼게요. (It's probably tomorrow, but I'll check.)

</summary>

F. Your friend asks if Korean is hard. You want to share your impression, not state it as fact.

<summary>Answer

제 느낌에는 생각보다 어렵지 않은 것 같아요. (In my feeling it doesn't seem as hard as I expected.)

</summary>

G. You're a bit uncertain — it might be one way, or it might not be.

<summary>Answer

그럴 것 같기도 하고, 아닐 것 같기도 해요. (It might be that way, and it might not.)

</summary>

H. You want to say you'll check before giving a definite answer.

<summary>Answer

확인하고 말씀드릴게요. (I'll check and let you know.)

</summary>

I. You're pretty sure but want to hedge slightly.

<summary>Answer

확실하지는 않은데, 아마 맞는 것 같아요. (I'm not 100% certain, but it's probably right.)

</summary>

J. Someone tells you something that you're not sure is true or false.

<summary>Answer

사실인지 잘 모르겠어요. 확인이 필요할 것 같아요. (I'm not sure if it's true. It probably needs verification.)

</summary>

📚

Certainty Spectrum

Expression	Certainty
확실해요	Very high
맞는 것 같아요	High
아마 -것 같아요	Medium
그럴 것 같기도 하고...	Medium-low
잘 모르겠어요	Low
전혀 모르겠어요	Very low

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Hedging Tip

확실하지는 않은데 is a perfect opener when you want to give an answer but can't guarantee it. It signals honesty upfront. Koreans appreciate this — they'd rather hear an honest hedge than an overconfident wrong answer.

</summary>

🔁

Want more reps?

For the next few conversations, notice when you're 100% sure and when you're guessing. Make a habit of using 확실해요 only for the first, and 아마 / 잘 모르겠어요 for the second.

📦 Practice Hub — Certainty vs. Uncertainty

Exercise 1 — Choose the Right Expression

Select the most natural certainty expression for each situation.

A. You have the train ticket in hand — the departure is confirmed at 7pm.

a) 아마 일곱 시인 것 같아요

b) 확실해요, 일곱 시에 출발해요

c) 잘 모르겠는데 일곱 시 같아요

<summary>Answer

b) 확실해요, 일곱 시에 출발해요 — You have the ticket. This is confirmed. Use 확실해요.

B. Someone asks if Seoul is the capital of Korea. You know this but want to state it naturally.

a) 아마 서울인 것 같아요

b) 잘 모르겠어요

c) 맞아요, 서울이 수도예요

<summary>Answer

c) 맞아요, 서울이 수도예요 — Known fact. State directly.

C. You think a café is probably open on Sundays, but haven't checked.

a) 확실히 일요일에 열어요

b) 아마 일요일에 열 것 같아요

c) 전혀 몰라요

<summary>Answer

b) 아마 일요일에 열 것 같아요 — Not confirmed. 아마 + -것 같아요 = probably.

D. You have absolutely no idea what the answer is.

a) 아마 그럴 것 같아요

b) 전혀 모르겠어요

c) 확실히 알아요

<summary>Answer

b) 전혀 모르겠어요 — Completely unknown. Use 전혀 모르겠어요.

E. You want to give an answer but signal upfront that you're not 100% sure.

a) 확실해요

b) 확실하지는 않은데, 아마 맞는 것 같아요

c) 전혀 모르겠어요

<summary>Answer

b) 확실하지는 않은데, 아마 맞는 것 같아요 — The honest hedge: give your best guess while flagging uncertainty.

F. Someone asks if a friend is coming tonight. You think so but didn't confirm with them.

a) 와요 — 확실해요

b) 아마 올 것 같아요

c) 전혀 안 올 것 같아요

<summary>Answer

b) 아마 올 것 같아요 — Not confirmed. Hedge with 아마.

G. You're genuinely unsure whether something is good or not.

a) 확실히 좋아요

b) 좋은지 잘 모르겠어요

c) 아마 나쁠 것 같아요

<summary>Answer

b) 좋은지 잘 모르겠어요 — Expressing uncertainty about quality.

H. You want to say you'll verify something before giving a definite answer.

a) 확실해요, 그냥 믿으세요

b) 확인하고 말씀드릴게요

c) 전혀 모르겠어요

<summary>Answer

b) 확인하고 말씀드릴게요 — "I'll check and let you know." The professional, humble response.

I. You're sharing a personal impression with uncertainty (it might be this way or not).

a) 맞아요, 그래요

b) 그럴 것 같기도 하고 아닐 것 같기도 해요

c) 확실해요

<summary>Answer

b) 그럴 것 같기도 하고 아닐 것 같기도 해요 — "It might be that way and might not." Genuine two-way uncertainty.

J. Someone asks if you speak Japanese. You studied a little but are far from fluent.

a) 확실히 해요

b) 전혀 못 해요

c) 조금 하는 것 같아요, 잘하지는 못해요

<summary>Answer

c) 조금 하는 것 같아요, 잘하지는 못해요 — "I can do a little, I guess — I'm not very good." Honest and natural.

📚

Certainty Spectrum

Expression	Level
확실해요	Very certain
맞아요 / 맞는 것 같아요	Certain / fairly certain
아마 -것 같아요	Probably
잘 모르겠어요	Not sure
확실하지는 않은데	Not 100%, but...
전혀 모르겠어요	No idea at all

⚠️

Don't Overuse 확실해요

Reserve 확실해요 for things you've personally confirmed. Using it for guesses sounds overconfident and can damage trust in Korean communication. When you're not sure, hedge — it's respected, not weak.

Exercise 2 — Korean → English Translation

Translate each sentence paying attention to the certainty level.

A. 확실해요, 내일 세 시에 만나요.

<summary>Answer

I'm certain — we're meeting tomorrow at 3.

B. 잘 모르겠는데, 아마 거기일 것 같아요.

<summary>Answer

I'm not sure, but it's probably there.

C. 전혀 모르겠어요.

<summary>Answer

I have no idea at all.

D. 확실하지는 않은데, 아마 맞는 것 같아요.

<summary>Answer

I'm not certain, but it's probably right.

E. 확인하고 말씀드릴게요.

<summary>Answer

I'll check and let you know.

F. 아마 내일 비가 올 것 같아요.

<summary>Answer

It will probably rain tomorrow.

G. 그럴 것 같기도 하고 아닐 것 같기도 해요.

<summary>Answer

It might be that way, and it might not.

H. 확실히 말하기 어려워요.

<summary>Answer

It's hard to say for certain.

I. 맞는 것 같은데, 확실하지는 않아요.

<summary>Answer

It seems right, but I'm not certain.

J. 사실인지 잘 모르겠어요.

<summary>Answer

I'm not sure if it's true.

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Vocabulary Cheat Sheet

Korean	English
확실하다	To be certain / definite
아마 / 아마도	Probably / Perhaps
전혀	Not at all / completely (not)
확인하다	To check / verify
말하기 어렵다	Hard to say
맞는 것 같다	Seems right

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Grammar Tip

아마 always pairs with a soft ending — 아마 -것 같아요 / 아마 -겠죠 / 아마 -거예요. Never say 아마 확실해요 — that's a contradiction. 아마 signals doubt, so the following clause must also hedge.

Exercise 3 — Complete the Sentence

Fill in the blank with the right certainty expression.

A. 저는 해요. 제가 직접 확인했어요. (certain)

<summary>Answer

확실 — 저는 확실해요. 제가 직접 확인했어요.

B. 잘 는데, 아마 열두 시일 것 같아요. (not sure)

<summary>Answer

모르겠 — 잘 모르겠는데, 아마 열두 시일 것 같아요.

C. 전혀 겠어요. 처음 들어보는 이야기예요. (no idea)

<summary>Answer

모르 — 전혀 모르겠어요. 처음 들어보는 이야기예요.

D. 내일 비가 올 것 같아요. (probably)

<summary>Answer

아마 — 아마 내일 비가 올 것 같아요.

E. 확실하지는 않은데, 맞는 것 같아요. (probably)

<summary>Answer

아마 — 확실하지는 않은데, 아마 맞는 것 같아요.

F. 확인하고 드릴게요. (I'll tell you)

<summary>Answer

말씀 — 확인하고 말씀드릴게요.

G. 그럴 것 같기도 하고 것 같기도 해요. (not)

<summary>Answer

아닐 — 그럴 것 같기도 하고 아닐 것 같기도 해요.

H. 확실히 기 어려워요. (to say)

<summary>Answer

말하 — 확실히 말하기 어려워요.

I. 것 같은데, 확실하지는 않아요. (seems right)

<summary>Answer

맞는 — 맞는 것 같은데, 확실하지는 않아요.

J. 사실인지 잘 . 확인이 필요해요. (not sure)

<summary>Answer

모르겠어요 — 사실인지 잘 모르겠어요.

📚

Sentence Starters

Starter	Certainty Signal
확실해요	Strong certainty
아마	Probability hedge
잘 모르겠는데	Low certainty opener
확실하지는 않은데	Hedged answer
전혀	Zero certainty intensifier
확인하고...	Deferred certainty

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Production Tip

Try the opener 확실하지는 않은데 before any answer you're not 100% sure about. It immediately signals honesty and invites the other person to verify. This single habit will make you sound dramatically more natural in Korean.

Exercise 4 — Dialogue Completion

Complete B's response with the appropriate certainty expression.

A. A: 오늘 회의가 세 시죠? B: (confirmed — you checked the calendar)

<summary>Answer

네, 확실해요. 캘린더에서 확인했어요.

(Yes, I'm certain. I checked the calendar.)

B. A: 내일 비 와요? B: (you think so, based on the forecast, but haven't checked)

<summary>Answer

아마 올 것 같아요. 날씨가 흐리거든요.

(It'll probably come. The sky is overcast.)

C. A: 그 식당 일요일에 열어요? B: (you have no idea)

<summary>Answer

전혀 모르겠어요. 확인해보는 게 좋을 것 같아요.

(I have no idea. You should probably check.)

D. A: 맞아요? B: (you think it's probably right but aren't certain)

<summary>Answer

확실하지는 않은데, 아마 맞는 것 같아요.

(I'm not certain, but it's probably right.)

E. A: 그 사람 내일 와요? B: (you'll verify before confirming)

<summary>Answer

확인하고 말씀드릴게요. 아직 물어보지 않았어요.

(I'll check and let you know. I haven't asked them yet.)

F. A: 한국어 어렵지 않아요? B: (your personal impression — not certain, depends on the person)

<summary>Answer

제 느낌에는 어렵지 않은 것 같아요. 사람마다 다를 것 같긴 해요.

(In my feeling it doesn't seem hard. I think it probably varies from person to person.)

G. A: 이거 사실이에요? B: (genuinely not sure)

<summary>Answer

잘 모르겠어요. 사실인지 확인이 필요할 것 같아요.

(I'm not sure. It probably needs verification.)

H. A: 여기가 맞아요? B: (you think it might be right or might not be)

<summary>Answer

맞는 것 같기도 하고 아닌 것 같기도 해요. 한번 확인해봐요.

(It seems right and it seems not right. Let's double-check.)

I. A: 그게 제일 좋은 방법이에요? B: (you're fairly sure but not 100%)

<summary>Answer

아마 그런 것 같아요. 확실히는 모르지만 제일 효율적인 것 같아요.

(Probably. I'm not certain, but it seems like the most efficient.)

J. A: 확실해요? B: (you are certain)

<summary>Answer

네, 확실해요. 제가 직접 확인했어요.

(Yes, I'm certain. I checked myself.)

📚

Useful Phrases

Phrase	Meaning
아직 물어보지 않았어요	I haven't asked yet
확인해보는 게 좋을 것 같아요	You should probably check
사람마다 다를 것 같아요	It probably varies by person
한번 확인해봐요	Let's double-check
제가 직접 확인했어요	I checked it myself

💡

Conversation Tip

확인하고 말씀드릴게요 is one of the most trusted phrases in Korean professional settings. It doesn't mean "I don't know" — it means "I value accuracy and won't give you a wrong answer." Use it confidently when you need more time to verify.

Exercise 5 — Free Speaking Practice

Express your real level of certainty for each prompt.

A. Tell someone what time you usually wake up — something you're very sure about.

<summary>Sample Answer

저는 매일 아침 일곱 시에 일어나요. 확실해요 — 항상 그래요.

(I wake up at 7am every morning. That's certain — I always do.)

B. Tell someone where you think a good restaurant is, but you haven't been in a while.

<summary>Sample Answer

아마 저 골목 안에 있을 것 같아요. 예전에 거기 갔는데, 확실하지는 않아요.

(It's probably down that alley. I went there before, but I'm not certain.)

C. Someone asks you a question you have absolutely no answer to.

<summary>Sample Answer

전혀 모르겠어요. 처음 들어보는 내용이에요.

(I have no idea. I've never heard of it.)

D. Express that something might be true or might not be — you genuinely can't decide.

<summary>Sample Answer

그럴 것 같기도 하고 아닐 것 같기도 해요. 확실히 말하기 어려워요.

(It might be that way and might not. It's hard to say for certain.)

E. Give your best guess about tomorrow's weather while signaling uncertainty.

<summary>Sample Answer

아마 맑을 것 같아요. 오늘 날씨가 좋아서요. 확실하지는 않아요.

(It'll probably be clear. The weather's nice today. But I'm not certain.)

F. Describe how good you are at something — honestly and with the right certainty level.

<summary>Sample Answer

한국어는 아직 잘 모르겠어요. 기초는 되는 것 같은데, 아직 공부 중이에요.

(I'm not sure how good my Korean is yet. I think I have the basics, but I'm still studying.)

G. Tell someone you're going to verify something before answering.

<summary>Sample Answer

확인하고 말씀드릴게요. 지금 바로 확인해볼게요.

(I'll check and let you know. I'll verify it right now.)

H. Share a personal impression of a place you've never visited but have heard about.

<summary>Sample Answer

아마 좋은 곳인 것 같아요. 이야기는 많이 들었는데, 직접 안 가봐서 확실하지 않아요.

(It's probably a nice place. I've heard a lot about it, but since I haven't been, I'm not certain.)

I. Use two different certainty expressions in one sentence.

<summary>Sample Answer

확실하지는 않은데, 아마 내일 비가 올 것 같아요.

(I'm not certain, but it'll probably rain tomorrow.)

J. Describe something you're very sure about and something you're very unsure about, back to back.

<summary>Sample Answer

한국어를 배우고 싶은 건 확실해요. 하지만 얼마나 걸릴지는 전혀 모르겠어요.

(I'm certain that I want to learn Korean. But how long it will take — I have no idea.)

📚

Sentence Starters

Starter	Certainty
확실해요	Very high
아마 -것 같아요	Probably
확실하지는 않은데	Hedged guess
잘 모르겠어요	Low certainty
전혀 모르겠어요	No idea
확인하고 말씀드릴게요	Will verify first

🌟

Speaking Challenge

Have a 6-exchange conversation (with a partner or yourself) about anything — plans, opinions, facts. In each response, deliberately choose a different certainty level. Try to use: 확실해요, 아마, 잘 모르겠어요, 확실하지는 않은데, 전혀 모르겠어요, and 확인하고 말씀드릴게요 — one per turn.

정직한 표현이 신뢰를 만들어요. ✨