In Korean there are several ways to turn a verb into a noun.
In English, we often use ‘-ing’ to do this; I like eating = I like the act of ‘to eat’.
I enjoy listening to music = I enjoy the act of ‘to listen to music’. And so forth.
There are three ways to do this in Korean.
V + (ㄴ/은,는,ㄹ/을)것
V + (ㄴ/은,는,ㄹ/을)건
V + (ㄴ/은,는,ㄹ/을)게
V + (ㄴ/은,는,ㄹ/을)걸
1. The most straightforward and common way is to replace the ‘다’ stem of the verb with -는 것. This is equivalent to saying ‘the act of doing [verb]’. This new verb-noun form can then be used as a topic (-는 건), as an object (-는 걸), or the subject (-는 게).
You can also use it by itself (-ㄴ/는/-ㄹ 거) when you want to express the act of doing [verb].
운전하는 걸 좋아해요 = I like driving.
일하는거나 공부하는것도 괜찮아요. = Working or Studying are ok.
V + 기
V + 긴
V + 기가
V + 길
2. The second way is to replace the ‘다’ stem of the verb with ‘기’. This is more equivalent to appending ‘-ing’ in English to the verb, but it is more natural with some verbs than others. ‘듣기’, ‘쓰기’, ‘읽기’ are some of the common verbs that usually appear in this form, but it just depends. You will see it with some verbs more often than others, it is less general than ‘는 것’. You can use it as a topic (-긴), as an object (-길), or as the subject (-기가).
You can also use it by itself (-기) when you want to express the act of doing [verb].
노래 듣길 좋아해요? = Do you like to listen to music?
영어 쓰긴 아주 어려워요. – Writing English is very difficult.
V + ㅁ/음
3. The third way is the least general way of making a noun out of a verb, and it is only used with certain verbs. The way is to remove ‘다’ stem of the verb, and either add ‘ㅁ’ to the bottom if it ends in a vowel, or append ‘음’ if it ends in a consonant. Again, this only works with some verbs like 잠 = sleep, 웃음 = laughter, 춤 = dance, etc and the verb is not treated as the ‘-ing’ form like the other methods but rather as a formal noun in itself. Many verbs are used with this form together like 춤을 추다, 꿈을 꾸다, etc.
It is also used as an ending (-ㅁ/음) when the level of politeness (반말,존댓말) is unknown.
좋은 꿈을 꾸세요! = Dream a good dream!
춤을 잘 춰요! – You can dance well!