Korean Topic Marker Vs. Subject Marker

안녕하세요? You probably learned the Korean topic maker 은/는 and subject marker 이/가. Then, you probably wonder how they are different! We can think of a situation that says

"Minsu is eating the meal." Which one do you have to choose?

The answer is both are correct! "민수가 밥을 먹어요." and "민수는 밥을 먹어요." both are grammatically right. Then why are there two markers? What is the point? How can we distinguish them? It can be tricky but I'll walk through with you to help you understand the differences between these markers.

1. The Topic Marker: 은/는

First, let's review each marker. 은/는 is the topic marker. It attaches to a noun and usually shows that the noun is the sentence's topic. It says what this sentence is about! It's one of an auxiliary marker. An auxiliary marker is a type of particle that adds additional meaning to a noun.

Depending on the last syllable of the noun, there are two forms, 은 and 는. If the last syllable has the final consonant, use 은. If the last syllable ends without the final consonant, please attach 는. Here are some examples.

• 저는 영진이에요. (As for me,) I'm Youngjin.

• ​이것은 책이에요. (As for this,) This is a book.

• ​민수는 밥을 먹어요. (As for Minsu,) Minsu is eating.

2. The subject marker: 이/가

이/가 is the subject marker. It's one of the case markers. A case marker shows the role of the noun. So the subject marker shows the noun is the subject of the sentence.

Depending on the last syllable of the noun, there are two forms, 이 and 가. If the last syllable has the final consonant, use 이. If it doesn't have the final consonant, you'll attach 가.

• 마이클이 학교에 가요. Michael is going to school.

• ​민수가 밥을 먹어요. Minsu is eating.

3. The difference between topic marker and subject marker

1

은/는 is an auxiliary marker. It can add some extra meaning. Usually, it has a contrasting vibe. 이/가 is just a subject marker. It doesn't have a comparison or contrasting vibe.

• (O) 철수는 알지만 영희는 모른다. Chul-su knows but Young-hee doesn't. 

• (?) 철수가 알지만 영희가 몰라요.

"지만" means "but" and combining two sentences into one. Because of "but" in the sentence, it is natural to use "은/는" which has a contrasting vibe.

2

이/가 usually is used to introduce a new noun. Once it is introduced you can continue with 은/는. It's not an absolute rule.

• 옛날 옛적에 호랑이가 살았습니다. Once upon a time, a tiger was living.

• 그 호랑이는 배가 고팠습니다. That tiger was hungry.

In the first sentence "a tiger" is introduced. So it has "이/가". In the second sentence, the tiger is mentioned again. So, we attach "은/는."

 3

이/가 is a case marker. That means you can not attach another case marker to it. 은/는 is an auxiliary marker, so it is relatively free to combine with case markers.

• 교실에는 없어요. It is not in the classroom.

• ​(X) 교실에가 없어요. - Wrong sentence!

교실 means a "classroom." 에 is a case marker that shows a place. That is why 교실 has the marker 에. 는 can attach to 에 adding the meaning of contrast to mean 'It can be in another place, but not in the classroom.' It can also be used to emphasize the classroom.

4

Continuing the example above, 은/는 shows the topic. 이/가 shows the subject. So, the sentence below is possible.

• ​교실에는 학생이 없어요. There is no student in the classroom.

By saying the topic marker 교실에는 you are adding a meaning like "As for classroom", or "I am talking about classroom". 학생 is the subject of this sentence.

5

이/가 is used when the focus of information is on the subject. To answer to "wh- questions" such as 누가(who), 뭐가(what), 이/가 is used. 은/는 is used when the focus of information is on the description.

• Q: 누가 민수예요? Who is Minsu.

       A: 제가 민수예요. I'm Minsu.​ 

• 저는 민수예요. (As for me) I am Minsu. 

For both examples above, the underlined parts are the important information. "제가" puts the focus on "I". "저는" puts the focus on the following information "민수예요."

Let's go back to the first question I asked. What will be the difference between "민수가 밥을 먹어요." or "민수는 밥을 먹어요." Can you tell me? Think about the answers before keep reading!

• 민수가 밥을 먹어요.

The focus is on Minsu. It just means "Minsu is eating the meal." Simple, right? The subject marker is not that difficult. You can use it just like an English subject.

• 민수는 밥을 먹어요.

The topic marker is the tricky one. Here are some possible meanings.

① The focus is on that he "is eating". 

②It can mean 민수 is eating but someone else is doing something else. Usually, there will be more context will be provided like 민수는 밥을 먹어요. 영희는 밥을 안 먹어요.(Minsu is eating. Younghui is not eating.)

③ 민수 maybe mentioned before and we may continue talking about him... For example, 민수가 식당에 있어요. 민수는 밥을 먹어요. Minsu is in the restaurant. Minsu is eating his meal.

4. Different version of "What is this?"

To ask "What is this?" we can use both topic and subject markers. However, there will be a little bit of differences. The main point here is whether you imply "contrasting" meaning or not.

• 이것이 뭐예요?: You are just simply asking "What is this?"

• 이것이 뭐예요? 이것이 뭐예요?: You can continue with a subject marker when you not implying a contrasting vibe.

• 이것이 뭐예요? 이것은 뭐예요?: Imagine you are in the market, and see something new and ask a seller "What is this?" and find another interesting-looking one and ask "What about this?" 

• 이것은 뭐예요? 이것은 뭐예요?: You ask about things with a "contrasting" vibe.

5. Warp-up

In this post, you've learned the differences between the subject marker and the topic marker. Let's review the key points with the chart.

이/가	은/는
Subject marker	Topic marker
Case marker (main marker)	Auxiliary marker (additional marker) It adds extra meaning.
It simply tells the subject of the sentence.	It tells the nouns is the topic of the sentence. It can imply a contrasting vibe.
It can be used to introduce a new noun.	Once the noun is mentioned, it can be continued with this.
It can't be attached to other case markers.	It can be attached to some other case markers.
The focus is on the subject. (who)	The focus is on the descriptive part (verb/adjective).