Every sentence has a subject, a verb, and usually an object. In Korean, the object gets marked with a particle: 을 (after consonant) or 를 (after vowel).
밥을 먹어요. I eat rice. (밥 + 을) 커피를 마셔요. I drink coffee. (커피 + 를)
Simple enough. But there's more to know about when Koreans actually use it. And when they drop it.
The basic rule
Object + 을 (after consonant-ending noun) Object + 를 (after vowel-ending noun)
| Noun | Ends in | Particle | Example |
|---|---|---|---|
| 밥 (rice) | ㅂ (consonant) | 을 | 밥을 |
| 물 (water) | ㄹ (consonant) | 을 | 물을 |
| 책 (book) | ㄱ (consonant) | 을 | 책을 |
| 커피 (coffee) | vowel | 를 | 커피를 |
| 음악 (music) | ㄱ (consonant) | 을 | 음악을 |
| 사과 (apple) | vowel | 를 | 사과를 |
When 을/를 gets dropped
In spoken Korean, 을/를 is very frequently dropped; especially in casual speech.
밥 먹었어? Did you eat? (밥을 → 밥, 을 dropped) 커피 마실래? Want to drink coffee? (커피를 → 커피) 음악 들어요. I'm listening to music. This is not incorrect. It's natural. Spoken Korean omits particles constantly in casual contexts.
Keep 을/를 in:
- Formal writing and speech
- When emphasizing the object specifically
- When the sentence would be ambiguous without it
을/를 with special verbs
Some verbs in Korean take 을/를 for what looks like a location or time. Not a direct object. These require 을/를 even though they're not "objects" in the traditional sense:
학교를 다니다 : to attend school (학교 = school, not a direct "object" but takes 를) 버스를 타다 : to ride the bus 산을 올라가다 : to go up the mountain 길을 건너다 : to cross the street
Desire verbs: 을/를 좋아하다, 싫어하다
을/를 always appears with verbs of liking/disliking when the object is a noun:
한국 음식을 좋아해요. I like Korean food. 이 노래를 좋아해요? Do you like this song? 더운 날씨를 싫어해요. I dislike hot weather.
을/를 with noun + 하다 compound verbs
Many Korean verbs are Noun + 하다 combinations. The noun before 하다 can take 을/를 or it can be treated as one unit:
공부를 하다 / 공부하다, to study (both correct) 운동을 하다 / 운동하다, to exercise 요리를 하다 / 요리하다, to cook
Using 을/를 slightly emphasizes the action as a deliberate activity.
Quick practice
Fill in 을 or 를 (and note where you could drop it in casual speech):
- 저는 음악___ 들어요. (I listen to music)
- 오늘 책___ 읽었어요. (I read a book today)
- 한국어___ 공부해요. (I study Korean)
- 친구___ 만났어요. (I met a friend)
Answers: 을 / 을 / 를 / 를 (all droppable in casual speech)
Particles are the skeleton of Korean sentences. They tell you who does what to whom. The best way to make them automatic is through massive exposure to real Korean. A structured Korean course's sentence-level drills put you in situations where you have to process particles at reading speed, not translation speed.