Seems like [Action]

This pattern expresses the speaker's assumption or guess about a situation, based on some observed evidence. It's equivalent to saying "it seems like," "I guess," or "it looks like" in English.

The ending changes depending on what it's attached to.

Action Verbs: -나 봐

Attach -나 봐 to the stem of action verbs for present tense guesses. For the past tense, use -았/었나 봐.

Present: 오다 → 오나 봐 (It seems to be raining.)

Past: 고장 나다 → 고장 났나 봐 (I guess it broke.)

Descriptive Verbs (Adjectives) & 이다: -(으)ㄴ가 봐

Attach -(으)ㄴ가 봐 to the stem of descriptive verbs.

Vowel stem: -ㄴ가 봐 (e.g., 배고프다 → 배고픈가 봐)

Consonant stem: -은가 봐 (e.g., 좋다 → 좋은가 봐)

Nouns: Use (noun)인가 봐 (e.g., 맛집 → 맛집인가 봐)

있다 / 없다

These two words behave like action verbs and take -나 봐.

있다 → 있나 봐

없다 → 없나 봐 (e.g., 아무도 없나 봐)

비가 오나 봐. / 배고픈가 봐. / 기계가 고장 났나 봐. / 맛집인가 봐.

While both patterns express conjecture, they have different nuances.

-나 보다 / -(으)ㄴ가 보다

This form implies that the speaker has just come to a conclusion based on new, direct evidence. It carries a sense of realization or discovery, like "Oh, I see now..." or "Ah, so it seems..."

Use when: You see dark clouds and say, 비가 오나 봐. (It looks like it's going to rain.)

-(으)ㄹ/는/(으)ㄴ 것 같다

This is a more general and versatile pattern for expressing an opinion, thought, or guess. It can be based on direct evidence, but it can also be a subjective feeling or something you heard indirectly. It's a neutral "I think..." or "it seems..."

Use when: You could say 비가 오는 것 같아요 based on seeing clouds, but also based on a weather forecast you read earlier.

In short, -나 보다 is for guesses triggered by immediate observation, while -는 것 같다 is a broader way to say "I think."

저 식당은 인기가 많나 봐. / 저 식당은 인기가 많은 것 같아. / 그 사람이 화났나 봐. / 그 사람이 화난 것 같아.

This pattern is frequently used in everyday conversation to comment on people's states or surrounding situations.

Observing People's Feelings or Actions

It's a natural way to guess what someone is feeling or doing based on their appearance or sounds you hear.

Feeling: 화났나 봐. (She looks angry.)

State: 피곤한가 봐. (He seems tired.)

Action: 요리하나 봐. (I smell food, so I guess they're cooking.)

Assessing a Situation

When you encounter a new situation, you can use this pattern to make a quick assessment.

문 닫았나 봐. (The lights are off, so I guess it's closed.)

다 팔렸나 봐. (The shelf is empty, so I guess it's all sold out.)

Giving a Soft Answer

It can also soften an answer when you're not 100% sure.

A: "민준 씨 어디 있어요?" (Where is Minjun?)

B: "집에 갔나 봐요." (I guess he went home. His bag is gone.)

화났나 봐. / 싸우나 봐. / 집에 갔나 봐. / 청소하나 봐.

This pattern is most common in spoken Korean and is considered informal or conversational. To make it polite, simply add -요 to the end. This shifts it from casual speech (반말) to standard polite speech (해요체).

Casual (반말): -나 봐 / -(으)ㄴ가 봐

Polite (해요체): -나 봐요 / -(으)ㄴ가 봐요

This form is generally not used in highly formal settings like academic writing or public speeches, where more definitive or objective language is preferred.

걔가 널 좋아하나 봐. / 걔가 호리 씨를 좋아하나 봐요. / 바쁜가 봐. / 바쁜가 봐요. / 문 닫았나 봐. / 문 닫았나 봐요.