🇰🇷 Lesson 4: Guessing & Inferring

You walk into the office on a Monday morning. Nobody is chatting. The team leader's door is shut. A colleague's umbrella is dripping by the desk, and someone has left a half-eaten 김밥 next to the keyboard. Without a single word being spoken, you already know a lot: it's raining, someone skipped breakfast to get in early, and the meeting behind that door is probably not going well.

Koreans have a famous word for this skill: 눈치, the art of reading a situation. And Korean grammar has a whole toolkit for saying "I'm guessing…", with each tool quietly signalling how sure you are and what your guess is based on. English mostly gets by with "I think", "probably", "must" and "might". Korean makes you choose, and the choice tells the listener something. That is what this lesson is about.

🧠 The Mental Model: Two Questions Behind Every Guess

Before you pick a form, ask yourself two questions:

1. What is my evidence? Something I can see or hear right now? Something I noticed about another person? Just general knowledge?
2. How sure am I? Pretty confident, or only "it's possible"?

You don't need to memorise this chart today. Keep it as a map: every section below zooms in on one row.

🔍 -(으)ㄴ/는/(으)ㄹ 것 같다: "It seems / I think"

You already know the three noun-modifier endings from the beginner course. 것 같다 simply hangs "it seems like the thing that…" off them, so the modifier carries the tense. That is the whole trick, and it is where most errors happen.

For a guess about the past (rather than a memory of it), -았/었을 것 같다 is also very common: 어제 많이 추웠을 것 같아요, "It must have been really cold yesterday" (said by someone who wasn't there).

The pair that matters most: -는 것 같다 vs -(으)ㄹ 것 같다

Both can describe the present, but the evidence differs. -는 것 같다 leans on something you are perceiving or already know; -(으)ㄹ 것 같다 is a prediction or a guess from the outside.

👀 -나 보다 / -(으)ㄴ가 보다: "I guess… (judging by that)"

This is the detective's ending. You have seen a clue, and you draw a conclusion about someone or something else. The clue is often stated in the same breath: 불이 꺼져 있네요. 다들 퇴근했나 봐요. ("The lights are off. I guess everyone's gone home.")

Watch the ㄹ-stems: ㄹ drops before -나 and before -ㄴ가, just as it does before -니까. 열다 → 여나 봐요, 살다 → 사나 봐요, 멀다 → 먼가 봐요, 길다 → 긴가 봐요.

A note on real usage: textbooks and TOPIK teach -(으)ㄴ가 보다 for adjectives, but in everyday speech you will also hear 바쁘나 봐요, 좋나 봐요. Both are understood; use -(으)ㄴ가 in writing and exams.

🧩 -는 모양이다: The Narrator's Version

모양 literally means "shape" or "appearance". -는 모양이다 says "it has the look of…", and in meaning it is very close to -나 보다: a fairly confident guess from observed evidence. The differences are in tone and grammar.

🎲 -(으)ㄹ지도 모르다: "It might…"

Literally "(I) don't know whether it will…", which is exactly how English speakers hedge: "Who knows, it might rain." This is the low-certainty end of the scale, and it goes hand in hand with 어쩌면 ("perhaps"), 혹시 ("by any chance") and 아마 ("probably").

A close neighbour is -(으)ㄹ 수도 있다 ("it's possible that"): 길이 막힐 수도 있어요. The two are often interchangeable. -(으)ㄹ지도 모르다 sounds a touch more like genuine uncertainty or worry; -(으)ㄹ 수도 있다 sounds like a neutral statement of possibility. Remember 모르다 is 르-irregular: 몰라요, 몰랐어요.

⚡ -겠- of Inference: The Instant Reaction

You met -겠- as "will / intend" in 제가 하겠습니다. Its other job is an instant inference from what is in front of you, often with emotion. It is the ending of empathy and first impressions.

Compare 맛있겠다! (a gut reaction, said on seeing the food) with 맛있을 것 같아요 (a considered opinion: "I think it'd be tasty"). When someone tells you their troubles, -겠어요 is the warmest thing you can say; it shows you are imagining their situation. The past form -았/었겠어요 reacts to something that already happened.

🧭 -(으)ㄹ 테니까: A Guess (or a Promise) as a Reason

테니까 is a contraction of 터 ("expectation") + 이다 + -니까. It has two uses, and the subject tells you which one you are looking at.

Unlike plain -(으)니까, the first clause is not a fact; it is what the speaker expects or intends. The second clause is usually a command, suggestion or request. There is no present-tense 는 version: *비가 오는 테니까 does not exist. In formal speech and writing you will also see the shorter -(으)ㄹ 테니: 곧 도착할 테니 잠시만 기다려 주십시오.

📊 Which One? Putting the Scale Together

💬 Dialogue: Reading the Room at Work

Notice how the certainty rises and falls: 생긴 것 같아요 (general sense), 때문인가 봐요 (clue: the boss's face), 길어질지도 모르겠네요 (only a possibility; 모르겠네요 is a softer, musing version of 몰라요), 나오실 테니까 (expectation used as advice), 쓴 모양이에요 (clue: the third coffee), 피곤하겠어요 (empathy).

🌏 Culture Note: 눈치 — 눈치, a word built on 눈 ("eye"), is the ability to sense unspoken moods and expectations. Someone who picks things up quickly is 눈치가 빠르다; someone oblivious is 눈치가 없다; and constantly checking others' reactions before acting is 눈치를 보다. In a culture where a lot goes unsaid, guessing grammar is not decoration. It is how people talk about the invisible layer of a conversation without making anyone lose face.

📰 Reading: 눈치를 배우는 중

A foreign employee writes a short blog post about learning 눈치 at a Korean company.

Six forms that all translate as "I think" or "it seems" can feel like a plateau: you understand them when you read them, but in conversation your mouth keeps choosing 것 같아요. That is completely normal at B1. Start by adding just one new form, perhaps -겠어요 for empathy, and let the others follow as you notice them in dramas and chats.

✏️ Practice

🧠 Check Your Understanding

❓ Common Questions

🔮 Looking Ahead

In Lesson 5: Endings That Carry Feeling, you'll learn the small sentence endings that make Korean conversation sound alive: -네요 and -군요 for surprise, -잖아요 for "you know", -거든요 for "you see", and -(으)ㄹ걸요, a close cousin of today's guessing forms. After today, you'll notice how many of them are about what the speaker knows and how they came to know it.