[Grammar] 이/가 vs 은/는 : Subject particle vs topic particle

We have learned Korean particles in the previous post(click).  This post is about subject particles and topic particles. The subject particles are  이 and 가, the topic particles are 은 and 는

Noun(ends with a consonant) + 이 

Noun(ends with a vowel) + 가

For example,

이름이 뭐예요?.  What is your name?
오늘이 며칠이에요? What date is today?
아기가 예뻐요. The baby is pretty.

And many people are confused the subject particle with the topic particle -은/는.

-은 and 는 are not subject particle. 

-은/는 can substitute -이/가(subject particle) and -을/를(object particle), which means you CAN’T use the topic particle and the subject/object particle for one noun.  We should use either topic particle or subject/object particle.

Noun(ends with a consonant) + 은

Noun(ends with a vowel) + 는

For beginners, we just need to know -은/는 are used for

1. when you introduce a noun

For example,

저는 이민수예요.  I am Lee Minsu.
저는 한국 사람이에요. I am Korean.
저는 28살이에요. I am 28 years old.
우리 한국어 선생님은 남자예요. My Korean teacher is a male.

2. when you compare two nouns

For example,

민수 씨는 사과를 좋아해요. 그런데 유진 씨는 사과를 안 좋아해요.
(Minsu likes apples, but Yujin doesn’t like apples)
– 민수 씨 and 유진 씨 are subjects.
* 민수 씨가는(X), 유진 씨가는(X)

민수 씨가 사과는 좋아해요. 그런데 (민수 씨가) 바나나는 안 좋아해요.
(Minsu likes apples, but he doesn’t like bananas.)
– 사과 and 바나나 are objects. 
* 사과를은(X), 바나나를은(X)

3. When you ask about new information, it is safe to use -이/가 and when you answer the question, you should -은/는

For example,

A: 이름이 뭐예요? What is your name?
B: 제 이름은 이민수예요. My name is Lee Minsu.

A: 오늘이 며칠이에요? What date is today?
B: 오늘은 8월 7일이에요. Today is August 7.

A: 이 분이 누구예요? Who is this person?
B: (이 분은) 제 어머니예요.  (This person is) My mother.

You can also listen to the pronunciation here.

#이 subject particle #가subject particle #subject particle #topic particle #topic #은는 #은topic #는topic #은subject #는subject #이/가vs은/는 #은는 topic #이가subject #subject marker #subject topic #Korean topic #은는 subject