Expressions with 아/어/여
In these cases, you have to check the last syllable of your verb stem to know how to conjugate the verb.
If that last syllable contains an 아 or an 오, you should add 아. (That includes syllables with 애, 얘, 야 or 요, though I’ve never seen any verb stems ending in the latter three.)
If it contains any other vowel (어, 우, 으 or 이) then add 어. Again, that includes 여, 유, 에 and 예.
If the verb is 하다, add 여. This makes it 해 plus the rest of the expression; the only time you’ll see 하여 is in formal situations, usually in writing. Even in this case, it’s not all that commonly used except in the past tense: 하였다.
Let’s take a look at 아/어/여서 and 았/었/였이다.
Verb stems ending in vowels can be a somewhat special; see page 26 on how to add 아/어/여 to vowels.
| 아/어/여서 a/eo/yeoseo | 았/었/였이다 at/eot/yeosida | ||
| Verbs with 아 or 오 | 작다 jakda | 작아서 jagaseo | 작았다 jagatda |
| Regular verbs with 어, 우, 으 or 이 (see below for exceptions) | 먹다 meogda | 먹어서 meogeoseo | 먹었다 meogeotda |
| 하다 | 하다 hada | 해서 haeseo | 했다 haetda |
(으)ㄴ/는, and ㄴ/는
Here’s where it gets interesting. First, check the title of the expression carefully to see which of the above sets you should use.
First, we have (으)ㄴ/는. When you see this, you have to go a step further and differentiate between active verbs and descriptive verbs. Descriptive verbs are like adjectives: 예쁘다 yeppeuda, 작다 jakda, 크다 keuda, 조용하다 joyonghada, 중요하다 jungyohada, and so on, while active verbs are verbs that describe actions: 먹다 meokda, 가다 gada, 걷다 geodda, 띄다 ttuida, and so on.
With (으)ㄴ/는 expressions, active verbs always take 는. Descriptive verbs are conjugated with ㄴ if they end in a vowel and 은 if they end in a consonant. Expressions that are conjugated in this way include (으)ㄴ/는데 and (으)ㄴ/는 탓에.
| (으)ㄴ/는데 (eu)n/neunde | (으)ㄴ/는 탓에 (eu)n/neun tase | ||
| Action verbs ending in a vowel | 하다 | 하는데 haneunde | 하는 탓에 haneun tase |
| Action verbs ending in a consonant | 먹다 | 먹는데 meokneunde | 먹는 탓에 meokneun tase |
| Descriptive verbs (adjectives) ending in a vowel | 예쁘다 | 예쁜데 yeppeunde | 예쁜 탓에 yeppeun tase |
| Descriptive verbs (adjectives) ending in a consonant | 작다 | 작은데 jageunde | 작은 탓에 jageun tase |
Finally, ㄴ/는 is added to verbs which use indirect speech particles; see page 304 on how to conjugate these. Basically, descriptive verbs take 다 plus whatever else you’re using in your expression (다고 하다 dago hada, 다기보다 dagiboda, 다면 damyeon) while active verbs take either ㄴ or 는. ㄴ is added to action verb stems ending in vowels while 는 goes after action verb stems ending in consonants.
How to Handle Verbs, Part 1: Changing Their Form
Changing Verbs to Nouns: (으)ㅁ, 기, (으)ㄴ/는 것
■ (으)ㅁ
This can be added to any kind of verb or even to nouns with 이 in case you need to change a noun into a verb and then back into a noun. It’s often used in writing and less so in speaking. You’re likely to see it on warning signs and other formal notices. There are a few common nouns which always use ㅁ: 꿈 kkum (“dream” from 꾸다 kkuda), 잠 jam (“sleep” from 자다 jada), and 얼음 eoleum (“ice” from 얼다 eolda) come to mind.
While 기 tends to have more to do with activities and appearances, (으)ㅁ is an introvert; it’s more concerned with thoughts and ideas.
ㅁ follows vowels and 음 follows consonants. 음 can follow the past tense, but not the future tense.
하다 hada (to do) > 함 ham (doing)
슬프다 seulpeuda (to be sad) > 슬픔 seulpeum (sadness)
살다 salda (to live) > 삶 salm (life) (irregular)
믿다 mitda (to believe) > 믿음 mideum (belief)
■ 기
기 gi also turns verbs into nouns and can be added to any kind of verb. It’s often used in speaking and there are quite a number of grammar points which demand 기 if you want to use a verb with it. Like (으)ㅁ, some words just like to be used with 기. I’m sure you’re all trying to improve your Korean 듣기 deudgi, 쓰기 sseugi, 말하기 malhagi and 읽기 ilggi.
(으)ㅁ is the “quiet, contemplative” way to turn verbs into nouns while 기 is the “extrovert.” 기 is normally used more for activities and actions as well as being more common in spoken Korean. It’s also used more in proverbs and slogans.
하다 hada (to do) > 하기 hagi (doing)
찾다 chajda (to find) >