What Does 이/가 Mean in Korean?
Written and reviewed by Jun and Jin, native Korean speakers
Published · Updated · How we write & review
After this page, you can mark the subject with 이/가 (i/ga), pick 이 or 가, and use it after 있다, 없다 and 아니다.
10-second answer
What does I/Ga mean?
이/가 (i/ga) 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 (eun/neun), which sets up what you're talking about.
민수가 왔어요.
minsu-ga wasseoyo.
Minsu came.
Literally: Minsu (subject) came.
Quick check — did that land?
1. Which particle follows 학생 (ends in a consonant) when marking it as subject?
이/가! Tiny particle, huge confusion.
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.
See also: 은/는 — the topic marker
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.
In casual speech the 가 is often dropped: 민수 왔어요 (minsu wasseoyo).
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. Spoken Korean shortens and drops particles all the time: 전 학생 아니에요 (jeon haksaeng anieyo).
시간이 있어요?
sigani isseoyo?
Do you have time?
Literally: Is there time?
있다/없다 (exist/not exist) also pair with 이/가. Just as common without the particle: 시간 있어요? (sigan isseoyo?)
More Words That Take 이/가 — and the Special Forms 제가, 내가, 네가, 누가
In one line: 이/가 marks the subject — the thing that does the action or is in the state. A handful of everyday verbs and adjectives always pair with it, even where English would use an object:
| Word | Pattern | Example |
|---|---|---|
| 되다 (to become) | [noun]이/가 되다 | 의사가 되고 싶어요. (uisaga doego sipeoyo.) — I want to become a doctor. |
| 필요하다 (to be needed) | [thing]이/가 필요하다 | 시간이 필요해요. (sigani piryohaeyo.) — I need time. |
| 좋다 / 싫다 (to be liked / disliked) | [thing]이/가 좋다 | 저는 겨울이 좋아요. (jeoneun gyeouri joayo.) — I like winter. |
| 아프다 (to hurt) | [body part]이/가 아프다 | 머리가 아파요. (meoriga apayo.) — I have a headache. |
좋다 is the one that surprises learners: 겨울이 좋아요 treats winter as the subject ("winter is pleasing"), while 좋아하다 takes an object — 겨울을 좋아해요. Both mean "I like winter"; the difference is covered in 좋다 vs 좋아하다.
Four very common words also change shape before 가: 저 → 제가, 나 → 내가, 너 → 네가, and 누구 → 누가. Because 내가 (I) and 네가 (you) sound almost the same in everyday speech, many people say 니가 for "you" — the National Institute of Korean Language notes that 니가 is used in real life but isn't standard, so write 네가. The full story of 제가 and 내가 is on the 나 vs 저 page.
Mistake: 의사를 되고 싶어요
되다 takes 이/가, never 을/를 — 의사가 되고 싶어요. The same goes for 아니다: 의사가 아니에요. And with 아프다, the body part takes 이/가; if you name the person at all, they take 은/는 (저는 머리가 아파요). But Koreans rarely say 저는 here — the speaker is obviously the one in pain, so the subject is usually dropped: 머리가 아파요 (meoriga apayo, "I have a headache").
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
2. 누가 왔어요? (Who came?) Which answer form fits best?
3. 저는 학생이 아니에요. What does 이 attach to here?
Related Knowledge
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You now know the topic and subject markers — the object marker completes the core particle set.
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