Topic and Subject Particles · 은/는, 이/가

4. Common mistakes

❌ Mistake 1 — Saying 저가

✖ 저가 했어요.
✔ 제가 했어요.
  je-ga hae-sseo-yo.

The subject form of 저 is 제가, not 저가. The topic form 저는 is correct and very common, so use 제가 only when you want to stress who did it.

❌ Mistake 2 — 는 after a consonant

✖ 물는 시원해요.
✔ 물은 시원해요.
  mu-reun si-won-hae-yo.

물 ends in a consonant, so the topic particle is 은, not 는. When you are not sure, say the noun and listen to the last sound.

❌ Mistake 3 — 이 after a vowel

✖ 친구이 와요.
✔ 친구가 와요.
  chin-gu-ga wa-yo.

친구 ends in a vowel, so the subject particle is 가, not 이. The same rule applies to 비가, 고양이가 and 날씨가.

❌ Mistake 4 — Using 누구가

✖ 누구가 와요?
✔ 누가 와요?
  nu-ga wa-yo?

The question word 누구 shrinks to 누 before 가. Learners often forget this, because the shape 누구가 looks regular. Always say 누가 for who as the subject.

❌ Mistake 5 — Topic particle for a new answer

Q: 누가 왔어요?
✖ 민수는 왔어요.
✔ 민수가 왔어요.
  min-su-ga wa-sseo-yo.

The question asks who, so the answer is the new information and needs 가. If you say 민수는 왔어요, it sounds like "Minsu, at least, came", and it suggests that someone else did not.