TTMIK Level 5 Lesson 5 - -(으)ㄴ가 보다

In the previous lesson, we looked at the structure -나 보다 [-na bo-da], which can be used with action verbs to mean “I guess …” or “I assume …”. In this lesson, we are going to look at how to say the same thing but with descriptive verbs.

For action verbs:
-나 보다 [-na bo-da]

Ex)
하다 → 하나 보다 (I guess they do ...)
오다 → 오나 보다 (I guess they come …)

For descriptive verbs:
-(으)ㄴ가 보다 [-(eu)n-ga bo-da]

Ex)
예쁘다 → 예쁜가 보다 (I guess it’s pretty …)
비싸다 → 비싼가 보다 (I guess it’s expensive …)
작다 → 작은가 보다 (I guess it’s small …)

For -이다 [-i-da] (= to be):
-이다 changes to -인가 보다

* Note that -이다 is not a descriptive verb on its own but it is usually combined with nouns to make a descriptive statement, so it is followed by -ㄴ가 보다.

Conjugation for -(으)ㄴ가 보다
Verb stems ending with a vowel + -ㄴ가 보다
Ex) 크다 → 크 + -ㄴ가 보다 = 큰가 보다

Verb stems ending with a consonant + -은가 보다
Ex) 작다 → 작 + -은가 보다 = 작은가 보다

Commonly accepted exceptions and irregularities
Even though the rule is that action verbs are followed by -나 보다 and descriptive verbs are followed by -(으)ㄴ가 보다, Korean people often use -나 보다 for descriptive verbs too, when the verb stem ends with a last consonant.

You can’t use -(으)ㄴ가 보다 for action verbs, but you will often hear Korean people using -나 보다 with descriptive verbs.

Ex)
작다 [jak-da] = to be small

Originally, 작 has to be followed by -(으)ㄴ가 보다 because it is a descriptive verb.

작은가 보다 [ja-geun-ga bo-da] = I guess it’s small.

But people often say 작나 보다 [jak-na bo-da] to mean the same thing.

Ex)
맵다 [maep-da] = to be spicy
→ 매운가 보다 or 맵나 보다

Present tense and past tense conjugations

[present tense]
-(으)ㄴ가 보다 → -(으)ㄴ가 봐요

[past tense]
For the past tense, you would add the suffix -았/었/였 to the verb stem of the descriptive verb, and after you do that, for ease of pronunciation, you need to always use -나 봐요 after -았/었/였.

So even though descriptive verb stems are followed by -(으)ㄴ가 봐요 in the present tense, they are always followed by -았/었/였나 봐요 in the past tense.

Ex)
아프다 [a-peu-da] = to be sick

→ [present tense] 아프 + -(으)ㄴ가 봐요 = 아픈가 봐요
→ [past tense] 아프 + -았/었/였나 봐요 = 아팠나 봐요

Exceptions
When the descriptive verb is composed of a noun and the verb 있다 [it-da] or 없다 [eop-da], i.e. 재미있다, 맛있다, 재미없다 or 맛없다, you need to add -나 봐요 after 있 or 없.

재미있다 → 재미있나 봐요 / 재미있었나 봐요
맛있다 → 맛있나 봐요 / 맛있었나 봐요

Sample sentences
1.
학생이 많아요. [hak-saeng-i ma-na-yo.] = There are a lot of students.
→ 학생이 많은가 봐요. [hak-saeng-i ma-neun-ga bwa-yo.] = I guess there are a lot of students.
→ 학생이 많았나 봐요. [hak-saeng-i ma-nat-na bwa-yo.] = I guess there were a lot of students.

2.
요즘 바빠요. [yo-jeum ba-ppa-yo.] = He’s busy these days.
→ 요즘 바쁜가 봐요. [yo-jeum ba-ppeun-ga bwa-yo.] = I guess he’s busy these days.
→ 바빴나 봐요. [ba-ppat-na bwa-yo.] = I guess he was busy.

3.
아이들이 졸려요. [a-i-deu-ri jol-lyeo-yo.] = The kids are sleepy.
→ 아이들이 졸린가 봐요. [a-i-deu-ri jol-lin-ga bwa-yo.] = I guess the kids are sleepy.

4.
그래요. [geu-rae-yo.] = It is so. That’s right.
→ 그런가 봐요. [geu-reon-ga bwa-yo.] = I guess so.

5.
이쪽이 더 빨라요. [i-jjo-gi deo ppal-la-yo.] = This way is faster.
→ 이쪽이 더 빠른가 봐요. [i-jjo-gi deo ppa-reun-ga bwa-yo.] = I guess this way is faster.