을/를 is the easiest Korean particle to understand and one of the easiest to misuse, because the rule is simple and the actual usage is full of exceptions.
The basic rule
을/를 marks the thing a verb acts on.
김치를 먹어요. — I eat kimchi. 책을 읽어요. — I read a book. 한국어를 배워요. — I learn Korean.
| After a consonant | After a vowel |
|---|---|
| 을 | 를 |
밥을 · 커피를 · 물을 · 영화를
That is the entire mechanical part.
Koreans drop it constantly
In spoken Korean, 을/를 disappears whenever the meaning is obvious.
밥 먹었어? — Did you eat? 커피 마실래? — Want some coffee? 이거 봐. — Look at this.
All natural. All missing 을/를.
This happens far more with 을/를 than with 이/가, because word order already tells you what the object is — it sits right before the verb.
So when should you include it?
- In writing
- In formal or careful speech
- When the sentence is long and the object is separated from the verb
- When you want emphasis
Early on, include it. Dropping particles correctly requires knowing when meaning would be lost, and that comes with experience.
The trap: verbs that take 이/가 instead
This is where learners lose points. Some Korean words that translate as English verbs are actually adjectives, and they take 이/가.
| Wrong | Right | Meaning |
|---|---|---|
| 커피를 좋아요 | 커피가 좋아요 | I like coffee |
| 시간을 없어요 | 시간이 없어요 | I have no time |
| 한국어를 어려워요 | 한국어가 어려워요 | Korean is hard |
The pattern: 좋다, 싫다, 있다, 없다, 어렵다, 쉽다, 필요하다 all take 이/가.
But watch this pair:
커피가 좋아요. — Coffee is good / I like coffee. 커피를 좋아해요. — I like coffee.
좋다 is an adjective and takes 이/가. 좋아하다 is a verb and takes 을/를. Same English translation, different Korean grammar.
Same with 싫다 / 싫어하다.
하다 verbs split in two
Many Korean verbs are a noun plus 하다, and the noun can take 을/를.
공부해요. = 공부를 해요. 운동해요. = 운동을 해요. 요리해요. = 요리를 해요.
Both are correct. Splitting it adds a small amount of emphasis on the activity, and it is what you do when you want to modify the noun:
한국어 공부를 해요. — I study Korean.
You cannot say 한국어를 공부를 해요 — one 을/를 per clause is the practical limit.
을/를 with movement verbs
A few verbs of movement take 을/를 where English would use a preposition.
버스를 타요. — I take the bus. 길을 건너요. — I cross the street. 산을 올라가요. — I go up the mountain.
타다 in particular catches people out, because English "get on" suggests a location particle. Korean treats the vehicle as the object.
Emphasis use
을/를 sometimes appears where it is not grammatically required, to push emphasis onto the word:
잠을 못 잤어요. — I couldn't sleep.
This is worth recognising rather than producing.
The short version
- Marks the object, goes right before the verb
- 을 after a consonant, 를 after a vowel
- Dropped constantly in speech, kept in writing
- 좋다 / 있다 / 없다 / 어렵다 take 이/가, not 을/를
- 좋아하다 takes 을/를
The last two lines cause more errors than everything else combined, and they are worth memorising as a pair rather than as a rule.
K-PATTO episodes are short conversations where these particles appear in normal speech — including the places Koreans drop them, which textbooks rarely show. The first ten are free at K-PATTO.