B2 · Upper Intermediate Chapter 15

Expressing Certainty and Logic

5 Total Rules
51 examples
5 min
Rules in This Chapter Quick Practice

Chapter in 30 Seconds

Master the art of logical deduction and unwavering certainty in natural Korean conversation.

  • Express logical probability based on external circumstances.
  • Deny possibilities and confirm absolute facts with authority.
  • Make educated guesses about the past and concede points gracefully.
Speak with conviction, reason with logic.

What You'll Learn

In this chapter, you're about to take a big leap and speak like a true Korean native! You'll move beyond just saying "I'm sure or I think"; you'll learn to precisely and subtly convey your level of certainty and logic in your speech. Imagine your friend hasn't arrived yet, and you see heavy traffic; by learning «-ㄹ/을 법하다,» you can say, "They're likely stuck in traffic." Or, when you're 100% sure something is impossible, with «-ㄹ 리가 없다,» you can decisively say, "There's no way!" In this lesson, you'll learn powerful tools like «-ㄹ/을 게 분명하다» to express yourself without a shred of doubt when you're absolutely certain about something. Wow, how great it is not to worry anymore! You can even use «-았/었을 것이다» to logically deduce about past events you didn't personally witness, like

They must have gone out yesterday.
These structures fit together like a puzzle, allowing you to express anything from a likely guess to absolute certainty in the best possible way. After this chapter, you'll be able to confidently express your opinions with reasoning and certainty in any conversation. You'll even learn how to use «-기는 하다» to concede a point politely before adding a small but and qualifying your statement. Ready for a much deeper and more authentic Korean conversation? Let's get started!

Learning Objectives

By the end of this chapter, you will be able to:

  1. 1
    By the end you will be able to describe likely scenarios using -ㄹ/을 법하다 based on logical reasoning.
  2. 2
    By the end you will be able to strongly negate impossible situations using -ㄹ 리가 없다.
  3. 3
    By the end you will be able to reconstruct past events logically using -았/었을 것이다.

Chapter Guide

Overview

Welcome, B2 Korean learners! Are you ready to elevate your Korean grammar to a truly native-like level? This chapter is your gateway to expressing certainty and logic with precision and nuance. Moving beyond simple "I think" or "I'm sure," you'll master expressions that allow you to convey exactly how confident you are about a statement, or how logically you've deduced something. This is a crucial step in achieving fluency and engaging in deeper, more authentic conversations.
At the B2 CEFR level, the expectation is to communicate effectively in a wide range of situations, and that includes expressing your thoughts with conviction and sound reasoning. By learning structures like -ㄹ/을 법하다 for likelihood, -ㄹ 리가 없다 for impossibility, -ㄹ/을 게 분명하다 for absolute certainty, and -았/었을 것이다 for logical past deductions, you'll gain the tools to articulate your opinions with confidence. You'll even learn -기는 하다 to gracefully concede a point before introducing a counter-argument. These advanced Korean grammar patterns will make your speech more sophisticated and natural, helping you sound less like a textbook and more like a native speaker.

How This Grammar Works

Let's dive into the powerful tools for expressing certainty and logic in Korean. First, for expressing that something is logically likely or probable, we use -ㄹ/을 법하다. This structure suggests that based on circumstances, something seems like it could reasonably happen. For instance, "그는 바빠서 못 올 법해요" (He's busy, so he's likely unable to come). When you're absolutely certain that there's no way something could be true, you'll use -ㄹ 리가 없다. It conveys strong disbelief or a logical impossibility. For example, "그가 거짓말을 했을 리가 없어요" (There's no way he lied).
To express absolute certainty, when you have no doubt whatsoever, the phrase -ㄹ/을 게 분명하다 is your go-to. It means "it's clear that" or "it must be." Imagine saying, "내일 비가 올 게 분명해요" (It's definitely going to rain tomorrow). For making a logical past guess, like deducing what must have happened, we use -았/었을 것이다. This is perfect for speculating about past events you didn't witness but can logically infer. For example, "그는 어제 집에 일찍 갔을 거예요" (He must have gone home early yesterday). Finally, to acknowledge with a 'but', or to concede a point before offering a qualification, we use -기는 하다. This softens your statement and adds nuance. For instance, "맛있기는 한데, 너무 비싸요" (It is delicious, but it's too expensive). Mastering these B2 Korean grammar structures will significantly enhance your expressive capabilities.

Common Mistakes

  1. 1✗ Wrong: "비 올 것 같아." (Sounds too casual/simple for strong certainty)
✓ Correct: "비가 올 게 분명해요." (It's definitely going to rain.)
*Explanation:* While "것 같다" expresses probability, -ㄹ/을 게 분명하다 conveys a much stronger, almost undeniable certainty, which is what the speaker truly intends here.
  1. 1✗ Wrong: "그가 어제 집에 일찍 가야 했어." (This implies 'had to go,' not 'must have gone' as a deduction)
✓ Correct: "그는 어제 집에 일찍 갔을 거예요." (He must have gone home early yesterday.)
*Explanation:* -았/었을 것이다 is specifically for logical deduction about past events. "가야 했어" means he *had* to go, indicating obligation, not inference.
  1. 1✗ Wrong: "이 음식은 맛있어. 하지만 비싸." (A bit blunt, lacks nuance)
✓ Correct: "이 음식은 맛있기는 한데, 너무 비싸요." (This food is delicious, but it's too expensive.)
*Explanation:* -기는 하다 acknowledges the positive aspect (delicious) first, then gently introduces the negative (expensive), making the statement more polite and nuanced than a direct "but."

Real Conversations

A

A

지영 씨가 아직 안 왔네요. (Jiyoung hasn't arrived yet.)
B

B

길이 많이 막히는 걸 보니, 늦을 법해요. (Seeing the heavy traffic, she's likely going to be late.)
A

A

그 어려운 시험에 그가 합격했을까요? (Do you think he passed that difficult exam?)
B

B

그가 밤새 공부한 걸 보면, 합격했을 리가 없어요. (Considering he studied all night, there's no way he didn't pass. / He must have passed.)
A

A

이 프로젝트는 내일까지 끝낼 수 있을까요? (Can we finish this project by tomorrow?)
B

B

팀원들이 열심히 하고 있으니, 분명히 끝낼 수 있을 게 분명해요. (Since the team members are working hard, it's clear we'll be able to finish it.)

Quick FAQ

Q

What's the main difference between -ㄹ/을 법하다 and just using 아마 (probably)?

While 아마 expresses general probability, -ㄹ/을 법하다 specifically implies that something is *logically reasonable* or *plausible* given the circumstances, often based on common sense or observable facts. It adds a layer of reasoned deduction.

Q

Can -았/었을 것이다 be used for future deductions?

No, -았/었을 것이다 is exclusively for logical deductions about *past* events. For future deductions, you would typically use -ㄹ/을 것이다 (e.g., "내일 비가 올 것이다" - It will probably rain tomorrow).

Q

Is -ㄹ 리가 없다 considered informal?

No, -ㄹ 리가 없다 is a versatile expression usable in both formal and informal contexts. Its formality depends more on the politeness level of the ending (e.g., -ㄹ 리가 없어요 vs. -ㄹ 리가 없어).

Q

When is -기는 하다 more appropriate than a simple "yes, but..."?

-기는 하다 is perfect when you want to acknowledge a point or agree with something, but immediately want to add a caveat, a criticism, or a different perspective. It softens the "but" and shows you've considered the other side.

Cultural Context

These expressions of certainty and logic are deeply embedded in how native Korean speakers communicate, reflecting a culture that values thoughtful consideration and polite nuance. Using structures like -ㄹ/을 법하다 allows for logical reasoning without sounding overly assertive, while -기는 하다 enables polite disagreement or qualification, crucial in a high-context society. You'll hear these B2 Korean grammar patterns frequently in everyday conversations, news analysis, and even debates, as they allow speakers to express strong opinions with appropriate levels of confidence and deference. Mastering them will not only improve your grammar but also your cultural understanding.

Key Examples (8)

1

이 시간쯤이면 차가 막힐 법해요.

At this hour, it's likely that there is traffic.

Logically Likely: -ㄹ/을 법하다
2

그 식당은 리뷰가 많아서 맛있을 법해.

That restaurant has lots of reviews, so it ought to be tasty.

Logically Likely: -ㄹ/을 법하다
3

James-ga geu don-eul humchyeoss-eul li-ga eops-eoyo.

There's no way James stole that money.

There's No Way... (-ㄹ 리가 없다)
4

Beolsseo maejin-il li-ga eopseo! Il-bun-bakk-e an jinatneunde.

No way it's already sold out! Only one minute has passed.

There's No Way... (-ㄹ 리가 없다)
5

그 영화는 재미있을 게 분명해요.

I'm sure that movie will be fun.

Expressing Absolute Certainty (-ㄹ/을 게 분명하다)
6

그는 벌써 잤을 게 분명해요.

I'm sure he already went to sleep.

Expressing Absolute Certainty (-ㄹ/을 게 분명하다)
7

어제 비가 많이 `왔을 거예요`. 땅이 다 젖어 있거든요.

It must have rained a lot yesterday. The ground is all wet.

Logical Past Guess: 'Must Have Done' (-았/었을 것이다)
8

민수 씨는 벌써 `퇴근했을 거예요`. 사무실 불이 꺼져 있어요.

Minsu must have already left work. The office lights are off.

Logical Past Guess: 'Must Have Done' (-았/었을 것이다)

Tips & Tricks (4)

💡

Focus on Logic

Always ask: 'Is there a logical reason for this?' If yes, use 법하다.
frontend.learn_grammar.from_rule: Logically Likely: -ㄹ/을 법하다
💡

Use for certainty

Only use this when you are 100% sure. If you are just guessing, use -ㄹ 것 같지 않다.
frontend.learn_grammar.from_rule: There's No Way... (-ㄹ 리가 없다)
💡

Check your evidence

Only use this when you have a reason. If you are just guessing, use -ㄹ 것 같다.
frontend.learn_grammar.from_rule: Expressing Absolute Certainty (-ㄹ/을 게 분명하다)
💡

Use for Evidence

Only use this when you have a reason for your guess.
frontend.learn_grammar.from_rule: Logical Past Guess: 'Must Have Done' (-았/었을 것이다)

Key Vocabulary (6)

분명하다 to be clear/certain 이유 reason 교통 체증 traffic jam 인정하다 to admit/acknowledge 가능성 possibility 확실히 certainly/definitely

Real-World Preview

clock

The Late Friend

Review Summary

  • V/A + -ㄹ/을 법하다
  • V/A + -ㄹ/을 리가 없다
  • V/A + -았/었을 것이다

Common Mistakes

The pattern is almost exclusively used with '없다' to show impossibility. Using '있다' makes it a rhetorical question which is much rarer.

Wrong: 그가 올 리가 있어요? (Is there a way he's coming?)
Correct: 그가 올 리가 없어요. (There's no way he's coming.)

In spoken Korean, -ㄹ 것이에요 is almost always contracted to -ㄹ 거예요. Using the uncontracted form sounds overly stiff.

Wrong: 어제 갔을 것이에요.
Correct: 어제 갔을 거예요.

-기는 하다 feels incomplete without a contrasting clause (하지만/한데). It is used to concede a point before adding a 'but'.

Wrong: 그는 똑똑하기는 해요. (He is smart.)
Correct: 그는 똑똑하기는 하지만 공부는 안 해요. (He is smart, but he doesn't study.)

Next Steps

You've just added a layer of sophistication to your Korean that many learners never reach. You are now capable of debating and reasoning like a true B2 speaker!

Watch a Korean mystery drama and narrate your theories using -ㄹ 게 분명해요.

Write 5 sentences about your childhood using -았/었을 것이다 for things you don't remember clearly.

Continue to: Inevitability and Close Calls

Quick Practice (10)

Select the formal version.

그가 올 게 분명해요.

✓ Correct! ✗ Not quite. Correct answer: 그가 올 게 분명합니다
Formal ending.

frontend.learn_grammar.from_rule: Expressing Absolute Certainty (-ㄹ/을 게 분명하다)

Fill in the blank with the correct form.

이 옷은 예쁘____ 비싸요.

✓ Correct! ✗ Not quite. Correct answer: 기는 하지만
The sentence requires a contrastive conjunction.

frontend.learn_grammar.from_rule: Acknowledging with a 'But' (-기는 하다)

Fix the sentence.

Find and fix the mistake:

그가 왔을 했다.

✓ Correct! ✗ Not quite. Correct answer: 그가 왔을 것이다
Wrong ending.

frontend.learn_grammar.from_rule: Logical Past Guess: 'Must Have Done' (-았/었을 것이다)

Choose the correct form.

그가 거짓말을 ___ 게 분명해요.

✓ Correct! ✗ Not quite. Correct answer: 했을
Past tense deduction.

frontend.learn_grammar.from_rule: Expressing Absolute Certainty (-ㄹ/을 게 분명하다)

Fill in the blank.

비가 ___ 법해요.

✓ Correct! ✗ Not quite. Correct answer: 올
Future modifier is required.

frontend.learn_grammar.from_rule: Logically Likely: -ㄹ/을 법하다

Choose the correct form.

그녀가 (먹다) ____.

✓ Correct! ✗ Not quite. Correct answer: 먹었을 것이다
Past stem + 을 것이다.

frontend.learn_grammar.from_rule: Logical Past Guess: 'Must Have Done' (-았/었을 것이다)

Fill in the blank.

내일 비가 ___ 게 분명해요.

✓ Correct! ✗ Not quite. Correct answer: 올
Vowel stem + ㄹ.

frontend.learn_grammar.from_rule: Expressing Absolute Certainty (-ㄹ/을 게 분명하다)

Fill in with the correct form of '비싸다'.

이게 ___ 리가 없어요.

✓ Correct! ✗ Not quite. Correct answer: 비쌀
Adjective stem + ㄹ.

frontend.learn_grammar.from_rule: There's No Way... (-ㄹ 리가 없다)

Choose the correct sentence.

Which sentence is grammatically correct?

✓ Correct! ✗ Not quite. Correct answer: 먹기는 했지만 맛없었어요
Tense consistency is key.

frontend.learn_grammar.from_rule: Acknowledging with a 'But' (-기는 하다)

Fix the error.

Find and fix the mistake:

그가 올 것 분명해요.

✓ Correct! ✗ Not quite. Correct answer: 그가 올 게 분명해요
Missing particle.

frontend.learn_grammar.from_rule: Expressing Absolute Certainty (-ㄹ/을 게 분명하다)

Score: /10

Common Questions (6)

Yes, use '갔을 법하다' for past conjecture.
It can be used in both formal and informal settings.
Yes, but only if you are certain it won't happen. For example, '내일 비가 올 리가 없어요' (It's impossible that it will rain tomorrow).
It can be if you use it to dismiss someone's opinion. Use it carefully.
Yes, use the past tense stem: 갔을 게 분명해요.
It expresses 100% certainty from the speaker's perspective.
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