Grammar · Particles
이 / 가, the subject particle
Pattern
[Subject] 이 / 가 [verb]
이/가 marks the subject, the thing that does something or is something. Use 가 after a vowel and 이 after a consonant. It presents new information, so a question word like 누가 'who' always takes it, and so does the answer. It is also the particle for the thing that exists, hurts or is liked with 있어요, 아파요 and 좋아요.
The mistake to avoid
저 and 나 change shape before 가: 제가 and 내가, never 저가. 누구 plus 가 likewise becomes 누가.
Examples
Romanisation help
화장실이 어디예요?
hwajangsiri eodiyeyo?
Where is the toilet?
누가 왔어요? 친구가 왔어요.
nuga wasseoyo? chinguga wasseoyo.
Who came? A friend came.
머리가 아파요.
meoriga apayo.
I have a headache.
비가 와요.
biga wayo.
It is raining.