은/는 for Everything: The Topic-vs-Subject Error

If you make one particle error in your first year of Korean, this is the one. Learners latch onto 은/는 — usually the very first particle they meet, in 저는 ("I") — and start treating it as the subject marker, sprinkling it on every noun that would be an English subject while 이/가 gathers dust. But 은/는 is not a subject marker at all: it's a topic marker. 이/가 marks the grammatical subject. They overlap just enough to fool you, and diverge exactly where it matters.

This page is about fixing the error. The full side-by-side decision procedure lives on the 은/는 vs 이/가 page; here we diagnose why English produces the mistake and drill the reflex out.

Why the English brain does this

English has no topic particle. Every English clause has a subject in subject position, and English handles the jobs Korean gives to 은/는 vs 이/가 with other machinery — stress ("MY friend came"), articles ("a king" vs "the king"), and clefts ("it was my friend who came"). Because none of that maps onto a particle, the learner does one of two things: maps every subject to the familiar 은/는, or scatters the two at random. Both feel fine in English and both are wrong in Korean.

The repair is to stop asking "what's the subject?" and start asking two other questions:

• Is this brand-new on the scene, or the answer to a who/what question? → 이/가.
• Is this something already known that I'm now commenting on or contrasting? → 은/는.

이/가 marks new information and the answer to "who/what"

When a person or thing enters the discourse for the first time, or when it's the focus that answers a question, it takes 이/가 (이 after a batchim, 가 after a vowel). A fresh event you're reporting on the spot — the weather, a knock at the door — is new information too.

There's a hard rule hiding in here: a question word as subject always takes 이/가, never 은/는 — and so does its answer. 누가 왔어요? ("who came?") can never be ×누는 왔어요, and you answer it with 가, not 는.

은/는 marks a known topic or a contrast

Once something is already on the table — mentioned, visible, obvious from context, or generally known — you can lift it up as the topic with 은/는 and say something about it. 은/는 also draws a contrast between two things.

The clearest demonstration is a two-sentence story. The character enters with 이/가 (new), then gets picked up with 은/는 (now known):

Flip the particles and it breaks: opening a story with 소녀는 sounds like you're resuming talk about a girl the listener already knows, and reintroducing her with 소녀가 in the second sentence sounds like a different girl just walked in.

Common Mistakes

Every error below is the same reflex — grabbing 은/는 because the noun looks like an English subject — showing up in a context that demands the focus/new-information 이/가.

1. Answering a "who" question with 는. The answer is the focus; it must take 가.

2. Reporting a fresh event with 는. A first-hand observation is new information.

3. Introducing a brand-new character with 는.

4. Jamming both particles on at once. Overcorrecting sometimes produces ×제가는, stacking subject + topic. You use one or the other, never both. (More on this on the double-marking page.)

The mirror-image error also exists — reaching for 이/가 to state a known topic, e.g. ×제 이름이 지훈이에요 as a plain self-introduction where the neutral choice is 제 이름은 지훈이에요. It's rarer, because the 은/는 overuse habit dominates, but it's the same fault seen from the other side: sorting nouns by "subjecthood" instead of by information status.

Key Takeaways

• 은/는 is a topic marker, not a subject marker; 이/가 is the subject marker. English has no topic particle, which is the root of the confusion.
• 이/가: new information, fresh events, and the answer to a who/what question (친구가 왔어요, 비가 와요, 제가 했어요).
• 은/는: a known topic or an explicit contrast (제 이름은 …, 커피는 …지만 차는 …).
• A question word subject is always 이/가 (누가 왔어요?), and so is its answer.
• In a story, characters enter with 이/가 and are picked up with 은/는 — swapping them changes who's who.