TTMIK Level 5 Lesson 4 - I guess, I assume (-나 보다)

In this lesson, we look at how to say “I guess ...”, “I assume ...” or “I suppose …” in Korean. We have already learned how to use -것 같다 [-geot gat-da] to express “I think …” or “it seems that …” in a previous lesson. Today’s key structure is somewhat similar to -것 같다 in meaning, but it has a stronger nuance of “I assume … based on this fact” or “I suppose … because …”.

-나 보다 [-na bo-da] = I assume, I suppose, I guess

This is usually only used when you are talking about people other than yourself. But when you talk about yourself using this -나 보다 structure, you are referring to yourself as a third person, making assumptions about why or how you have done something.

Ex) I guess you don’t like coffee.
Ex) I guess I never heard about it.

-나 보다 is only used with action verbs.
For descriptive verbs, you need to use a different structure, which we will introduce in the next lesson.

Conjugation:
[present tense]
Verb stem + -나 보다 [-na bo-da]

[past tense]
Verb stem + -았/었/였 + -나 보다 [-at/eot/yeot + -na bo-da]

Ex)
하다 = to do
하 + -나 보다 = 하나 보다 [ha-na bo-da] = I guess they do + something

→ [present tense] 하나 봐요.
→ [past tense] 했나 봐요

(For future tense, you need to use a different structure, but we will cover that in a future lesson.)

Examples:
1.
모르다 [mo-reu-da] = to not know
모르 + -나 봐요 = 모르나 봐요. [mo-reu-na bwa-yo.]
= I guess he(she/they) don’t know.

[past tense]
몰랐나 봐요. [mol-lat-na bwa-yo.]
= I guess he(she/they) didn’t know.

2.
없다 [eop-da] = to be not there, to not exist
없 + -나 봐요 = 없나 봐요. [eop-na bwa-yo.]
= I guess he(she/they/it) is not there.

[past tense]
없었나 봐요. [eop-seot-na bwa-yo.]
= I guess he(she/they/it) wasn’t there.

3.
재미있다 [jae-mi-it-da] = to be fun, to be interesting
재미있 + -나 봐요 = 재미있나 봐요. [jae-mi-it-na bwa-yo.]
= I guess it’s fun. / I suppose it’s interesting.

[past tense]
재미있었나 봐요. [jae-mi-i-sseot-na bwa-yo.]
= I guess it was fun.

4.
사다 [sa-da] = to buy
사 + -나 봐요 = 사나 봐요. [sa-na bwa-yo.]
= I guess he(she/they) buys.

[past tense]
샀나 봐요. [sat-na bwa-yo.]
= I guess he(she/they) bought.

Sample sentences:
1. 효진 씨는 아직 모르나 봐요.
[hyo-jin ssi-neun a-jik mo-reu-na bwa-yo.]
= I guess Hyojin still doesn’t know.

2. 또 비가 오나 봐요.
[tto bi-ga o-na bwa-yo.]
= I guess it’s raining again.

3. 어제 재미있었나 봐요.
[eo-je jae-mi-i-sseot-na bwa-yo.]
= I guess it was fun yesterday. / I assume you had a good time yesterday.

4. 아무도 없나 봐요.
[a-mu-do eop-na bwa-yo.]
= I guess there’s no one there.

5. 고장났나 봐요.
[go-jang-nat-na bwa-yo.]
= I guess it broke.