What Does 이/가 Mean in Korean?
10-Second Answer
이/가 is a Korean particle that marks the subject of a sentence — often the answer to "who?" or "what?". It tends to identify or spotlight something, in contrast with 은/는, which sets up what you're talking about.
민수가 왔어요.
minsu-ga wasseoyo.
Minsu came.
Literally: Minsu (subject) came.
Start With the Example
민수 is the name, 가 marks it as the subject, and 왔어요 means "came." The sentence answers an implied question: who came? Minsu.
이 or 가?
Like 은/는, the choice depends on the final sound of the noun.
| Noun ends in… | Use | Example |
|---|---|---|
| a consonant | 이 | 학생 + 이 → 학생이 |
| a vowel | 가 | 민수 + 가 → 민수가 |
What 이/가 Actually Does
이/가 tends to appear when you're identifying, presenting, or emphasizing WHO or WHAT is doing something — especially when answering a "who/what" question.
누가 왔어요? — 민수가 왔어요.
nuga wasseoyo? — minsu-ga wasseoyo.
Who came? — Minsu (is the one who) came.
뭐가 문제예요?
mwoga munjeyeyo?
What's the problem?
뭐 (what) + 가 — identifying the problem.
제가 vs 저는: 제가 학생이에요 answers 'who is the student?' — 저는 학생이에요 simply introduces yourself as a student. Same words, different focus.
이/가 Also Appears After 아니다 and 있다/없다
저는 학생이 아니에요.
jeoneun haksaengi anieyo.
I'm not a student.
아니다 (to not be) pairs with 이/가, not 을/를.
시간이 있어요?
sigani isseoyo?
Do you have time?
Literally: Is there time?
있다/없다 (exist/not exist) also pair with 이/가.
Common Mistakes
Mistake #1 — "이/가 = subject, so translate it as 'is'"
이/가 doesn't mean "is" — that's the verb 이다/있다 doing the work. 이/가 just marks which noun is the subject.
Mistake #2 — Treating 이/가 and 은/는 as interchangeable
They often produce grammatically valid sentences either way, but the FOCUS changes. See the comparison page for the full picture.
Mini Quiz
1. Which particle follows 학생 (ends in a consonant) when marking it as subject?
2. 누가 왔어요? (Who came?) Which answer form fits best?
3. 저는 학생이 아니에요. What does 이 attach to here?
Related Knowledge
Learn Next
You now know the topic and subject markers — the object marker completes the core particle set.
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Start today's study →Last updated: 2026-08-10 · Written and reviewed by a native Korean speaker.