Korean -나 보다: "It Seems That..." in Your Diary

Your coworker has been smiling at her phone all morning. The street outside is wet and nobody is carrying an umbrella. A friend has not answered your message since last night. You did not see the reason, but you can read the clues. Korean has a pattern for exactly this kind of guess: -나 보다 (and its partner -(으)ㄴ가 보다). It means "it seems that...", and it works from evidence you can actually see or hear.

How to form it

Word type	Present	Past	Example
Verb	stem + 나 보다	았/었나 보다	친구가 요즘 바쁘게 지내나 보다. — My friend seems to be keeping busy lately.
있다 / 없다	있나 보다 / 없나 보다	있었나 / 없었나 보다	집에 아무도 없나 보다. — Nobody seems to be home.
Adjective	stem + (으)ㄴ가 보다	았/었나 보다	오늘은 많이 피곤한가 보다. — I seem to be very tired today.
Noun	인가 보다	이었나 / 였나 보다	저 사람이 선생님인가 보다. — That person seems to be a teacher.

Verbs in the present take 나, with a past marker added before it for earlier events: 비가 왔나 보다 ("it seems it rained"). Adjectives and 이다 take -(으)ㄴ가 보다 in the present, and 았/었나 보다 for the past: 어제는 추웠나 보다. The verb 보다 stays as it is. You also see -는가 보다 for verbs, which sounds a bit more formal or written. Both are fine.

In casual speech the ending is shortened: 비가 오나 봐요 / 비가 오나 봐. In a diary written in plain style, use 보다.

What it means: a guess backed by a clue

-나 보다 says: "I did not see it directly, but from what I can see or hear, this is probably the case." The clue comes first, then the guess. This is why it pairs so well with -는 걸 보니(까) ("judging from the fact that..."):

• 동료가 계속 웃는 걸 보니 좋은 일이 있나 보다. — Judging by how she keeps smiling, she must have some good news.
• 길이 젖어 있는 걸 보니 밤에 비가 왔나 보다. — The road is wet, so it must have rained during the night.
• 가게 앞에 줄이 길다. 맛집인가 보다. — There's a long line outside the shop. It must be a famous place.
• 친구가 답장이 없다. 많이 바쁜가 보다. — My friend isn't replying. They must be very busy.
• 앞집 불이 꺼져 있다. 여행을 갔나 보다. — The lights are off next door. They must have gone on a trip.

It also covers a surprise about yourself. If you notice the signs in your own body, the same pattern works: 벌써 졸린 걸 보니 내가 많이 피곤한가 보다 ("I'm sleepy already, so I must be really tired").

-나 보다 vs -는 것 같다 vs -는 모양이다

Pattern	Feeling	Example
-나 보다	A guess from clues you noticed	비가 오나 보다. (People outside are holding umbrellas.)
-는 것 같다	Works with or without a clue, and is more subjective	비가 오는 것 같다. (It feels like it's raining, from the sound or just a sense.)
-는 모양이다	Similar to -나 보다, a bit more neutral and objective; common in both speech and writing	비가 오는 모양이다. / 바쁜 모양이야.

The difference: with -나 보다 you are reporting from a bit of distance, based on what you noticed, so it is not for your own opinions. -는 것 같다 works with or without a clue and is more subjective. The simple test: can you name the clue? If yes, -나 보다 fits. If you are just going with a feeling, -는 것 같다 is the safer choice.

-나 보다 mostly describes the present or the past. For a guess about the future, plain -(으)ㄹ 것 같다 or -겠다 is the usual tool. When you do have a clue, -(으)려나 보다 or -(으)ㄹ 건가 보다 also works: 하늘을 보니 비가 오려나 보다 ("looking at the sky, it seems it's going to rain").

Honorifics

Put the honorific -시- before 나: 선생님이 아직 안 오셨나 보다. — The teacher doesn't seem to have arrived yet. For a person you should honor, 계시다 becomes 계시나 보다.

Common mistakes

Mistake	Fix	Why
친구가 피곤한 보다 ✗	친구가 피곤한가 보다 ✓	After an adjective you need 가 as well: -(으)ㄴ가 보다.
저 사람이 학생나 보다 ✗	저 사람이 학생인가 보다 ✓	A noun needs 인가 before 보다.
비가 왔나 봤다 ✗	비가 왔나 보다 ✓	The past goes before 나, and 보다 stays the same.
날씨가 춥나 보다 △	날씨가 추운가 보다 ✓	You can hear -나 보다 after some adjectives in speech, but -(으)ㄴ가 보다 is the standard shape. Stick with it in writing.
나는 지금 점심을 먹나 보다 △	나는 지금 점심을 먹고 있다 ✓	You know what you are doing, so a guess sounds odd. Use it only for what you discover from signs.

Try it in tonight's entry

Look back at your day for clues and the guesses you made. Fill in each line:

• 옆자리 동료가 오늘 일찍 퇴근하는 걸 보니 약속이 있나 보다.
• 엘리베이터가 계속 고장인 걸 보니 아직 수리 중인가 보다.
• 하루 종일 졸린 걸 보니 잠을 푹 못 잤나 보다.
• 카페에 사람이 하나도 없는 걸 보니 오늘 쉬는 날인가 보다.

This pattern turns a diary from a list of events into a small detective story: what you noticed, and what you think it means. Want to check that your -나 보다 sentences sound natural? Write your diary at kdiaryai.com and get instant corrections.