One of the highest-leverage patterns in Korean is something called nominalization: turning a verb or adjective phrase into a noun. In English, we do this with "-ing": "I like running." / "Studying is hard."
Korean uses ~는 것 for present/habitual verbs, ~(으)ㄴ 것 for past/completed, and ~(으)ㄹ 것 for future/hypothetical.
Master this pattern and an enormous range of expressions opens up.
The basic structure
Verb stem + 는 것 (geot) = "the act of [verb]ing" / "the thing that [verb]s"
가는 것 : the act of going / going 먹는 것 : eating / the thing one eats 공부하는 것 : studying
것 literally means "thing." 것이 → 게, 것은 → 건, 것을 → 걸 in casual speech.
Using it as a subject
한국어를 배우는 것은 어려워요. Learning Korean is difficult. (한국어를 배우는 것) = subject = "learning Korean"
매일 운동하는 것이 중요해요. Exercising every day is important.
Using it as an object: likes, dislikes, preferences
~는 것을 좋아하다, to like doing something ~는 것을 싫어하다, to dislike doing something
저는 음악을 듣는 것을 좋아해요. I like listening to music. 요리하는 것을 즐겨요. I enjoy cooking. 아침에 일찍 일어나는 것이 싫어요. I dislike waking up early. In casual speech: 음악 듣는 거 좋아해요. (것이 → 거)
것 같다 : expressing guesses and impressions
This is one of the most useful patterns in Korean:
Verb/adj + 는 것 같다: it seems like / I think / it appears that
비가 올 것 같아요. It looks like it's going to rain. 피곤한 것 같아요. You seem tired. 맞는 것 같아요. It seems correct. 이게 더 좋은 것 같아요. I think this one is better. This softens statements and is used constantly in polite conversation to avoid being too direct.
Past nominalization: ~(으)ㄴ 것
For describing something that happened:
먹은 것 : what was eaten / something that was eaten 한 것 : what was done
제가 한 것이 아니에요. It's not something I did. 어제 먹은 것이 맛있었어요. What I ate yesterday was delicious.
Future nominalization: ~(으)ㄹ 것
For describing future or hypothetical things:
갈 것 : something/someone that will go 먹을 것 : something to eat
먹을 것을 샀어요. I bought something to eat. 내일 할 것이 많아요. There's a lot to do tomorrow.
것이다 : emphasis and explanation
Verb + ~(으)ㄹ 것이다 can also express strong prediction or future plans:
비가 올 거예요. It will rain. (것이에요 → 거예요 casual) 잘 될 거예요. It'll work out. (reassurance)
Combining with other patterns
것 combines with particles to create common fixed expressions:
~는 것 같다: seems like (covered above) ~는 것보다: compared to [doing X] ~는 것은 아니다: it's not that [X] ~는 것이 좋다: it's good to [X] / you should [X]
일찍 자는 것이 좋아요. It's good to sleep early. / You should sleep early. 혼자 하는 것보다 같이 하는 게 더 좋아요. Doing it together is better than doing it alone.
~는 것 appears in hundreds of fixed expressions and patterns. If you've been feeling like Korean has "too many grammar points": this one pattern underlies a large portion of them.
For a structured progression through patterns like this, with exercises that show how they connect, see my Korean Grammar Essentials workbook. A structured Korean course sequences these patterns in the order they naturally build on each other, so you're never learning something in isolation.