2 · Particles
은/는 or 이/가: choosing between topic and subject
topic versus subject
이/가 brings in something new or answers "who?" and "what?"; 은/는 talks about something already known or sets it against something else.
Both particles can stand on the subject, and that is why English speakers keep asking which one is right. A good test is the question the sentence answers. 민수는 학생이에요 answers "what is Minsu?" — the news comes after the particle. 민수가 학생이에요 answers "which one is the student?" — the news is Minsu himself. 은/는 puts the weight on what follows it, 이/가 on the word in front of it.
New and known. In a story, a person enters with 이/가 and is talked about with 은/는 from then on: 옛날에 한 남자가 살았어요. 그 남자는 아주 가난했어요. The first sentence introduces him; the second already has him in mind and says something about him.
Question words. A question word that is the subject always takes 이/가 — 누가, 뭐가, 어디가, 어느 것이 — because it asks for something nobody has in mind yet, and the answer keeps 이/가 because it fills the same gap: 뭐가 맛있어요? 김밥이 맛있어요. When the question word is in the comment instead, the subject may be a topic: 화장실은 어디예요?
Contrast and clauses. Contrast always takes 은/는, and so do many negative sentences, which tend to imply "but something else, yes": 술은 안 마셔요. Inside a clause that sets a condition or describes a noun, on the other hand, the subject takes 이/가, because the clause is not what the whole sentence is about: 친구가 오면 같이 가요.
The form
| describing someone known | 민수는 학생이에요. |
| answering which one | 민수가 학생이에요. |
| question word as the subject | 누가 왔어요? |
| known topic, question word after it | 화장실은 어디예요? |
| contrast | 술은 안 마셔요. |
| subject inside a condition | 친구가 오면 같이 가요. |
The rules one by one
The form this topic is aboutThe word that calls for it
A question word that is the subject takes 이/가, never 은/는, and so does the answer.
뭐가 제일 맛있어요?What is the most delicious?
Something new enters with 이/가; once it is known, it continues with 은/는.
어제 친구가 왔어요. 그 친구는 요리사예요.A friend came yesterday. That friend is a cook.
은/는 puts the weight on the comment after it; 이/가 puts it on the noun in front.
제가 반장이에요.I am the class representative (it is me).
Contrast takes 은/는, and so do many negative sentences.
고기는 먹어요. 생선은 안 먹어요.Meat I eat. Fish I do not.
The subject inside a clause that sets a condition takes 이/가.
비가 오면 집에 있을 거예요.If it rains, I will stay at home.
A closer look
Why 은/는 can sound like a contrast when none was meant
Because 은/는 marks what is already on the table, putting it on something that was not the topic makes the listener wonder why. Asked 다들 왔어요?, "has everyone come?", the reply 민수 씨는 왔어요 reports one arrival and leaves the others hanging: Minsu came — and the rest?
The same effect makes 은/는 natural in polite refusals and hedges. 오늘은 좀 바빠요, "today I am a bit busy", suggests that another day would be fine, without having to say so. An English speaker would add "today, though"; Korean leaves it to the particle.
How to spot it
- 누가
- 뭐가
- 어디가
- 어느 것이
- 은/는
- 이/가
Example sentences
누가 창문을 열었어요?Who opened the window?
제 동생이 열었어요.My younger sibling did.
어느 우산이 지수 씨 거예요?Which umbrella is yours, Jisu?
화장실은 어디예요?Where is the toilet?
수영은 좋아해요. 그런데 달리기는 싫어해요.Swimming I like. Running, though, I dislike.
옛날에 한 할머니가 살았어요. 그 할머니는 고양이를 아주 좋아했어요.Once upon a time there lived an old woman. She loved cats very much.
8 more example sentences
뭐가 제일 좋아요?What do you like best?
이 케이크가 제일 맛있어요.This cake is the most delicious.
제 고양이는 눈이 파래요.My cat has blue eyes.
어디가 아파요?Where does it hurt?
민수 씨는 오늘 안 와요.Minsu isn't coming today.
시간이 있으면 같이 영화 봐요.If you have time, let's watch a film together.
여기가 제 방이에요.This is my room.
오늘은 제가 낼게요.I'll pay today.
Worth knowing (1)
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What is your name?
The most common question at a first meeting uses 이: 이름이 뭐예요? The name is the subject and 뭐 fills the gap after it. With 은 — 이름은 뭐예요? — the question sounds like it is moving on to the name as the next item, after something else has already been asked.
이름이 뭐예요?What is your name?
The trap English speakers fall into
Watch out
A question word asks for something unknown, and 은/는 marks what both speakers already have in mind — the two cannot go together. The subject question word takes 이/가 (누가, 뭐가), and the answer keeps it: 제 친구가 불렀어요.
New, or the answer to "who?": i or ga. Already known, or set against something else: eun or neun.
Your turn
10 exercises on this topic. Your answers are checked in the browser; none of them leaves your device.