How to distinguish 은/는 and 이/가

안녕하세요~! 토미입니다!

Today, I will teach you how to distinguish the topic marker 은/는 and the subject marker, 이/가.

In Korean grammar, the concept of particles takes an important role in defining the relationship that words have in a sentence.

In Korean, you should add a particle right after each main word so that it is easy for the listener to understand.

The most basic particles you should know is 은, 는, 이 and 가. 은 and 는 are called “topic marking particles” or “topic markers”. The topic marker is literally the topic of a sentence. So you basically focus on what the sentence is talking about.

Conversely, 이 and 가 are called “subject marking particles” or “subject markers”. It shows that the noun has a strong relationship with the vowel, and it is often the answer to the questions of who or which.

Native Korean speakers properly use these particles depending on the various meanings they want to convey.

However, it is quite difficult for Korean learners to understand the differences of each particle and use them correctly in the actual conversation.

That happens for people who have learned Korean and even lived in Korea for a long time.

Therefore, here I will give you a clear explanation of each particle and examples.

So I am sure you can get the basic idea.

은 /는 : topic markers

Topic marking particles indicate the topic of a sentence, what the sentence is about. You use 은 for words, which end with a consonant, and 는 for words which end with a vowel. Now, I will show you some examples.

저는 한국사람이에요. (I am Korean.)

This sentence has the topic marker right after a word 저, which is “I”, and says, “I am Korean.” So, the topic of the sentence is 저. 저는 indicates that the sentence is going to talk about 저 and you can tell it is a self-introduction.

이 책은 재미있어요. (This book is interesting.)

The next one has the topic marker after 이 책, this book, and says, “This book is interesting.” Here, the sentence is talking about a book and telling how it is interesting.

이 가방은 디자인이 좋아요. (As for this bag, the design is good.)

The last one has two particles but, as for the topic markers, it is attached after 이 가방, this bag, so you can immediately tell the sentence is talking about a bag.

The sentence goes 디자인이 좋아요, which means the design is good.

Accordingly, the meaning of the sentence is “As for this bag, the design is good.”

As you can see, you use 은/는 for the main topic of each sentence. In this way, in Korean grammar, you make it clear what you are going to talk about by marking with these topic markers and continue a sentence by describing what it is or how it is.

This is the basic and easiest use of 은/는.

이/가: subject markers

Subject markers show a strong relationship between a noun and a verb, and identify who/what initiates an action.

In other words, words marked by 이/가 are who/what takes an action.

It is often used as an answer to questions like who did it.

You use 이 for words which end with a consonant, and 가 for words which end with a vowel.

Let’s say you are about to eat a piece of cake you left in the refrigerator last night, but find it gone for some reason.

You probably suppose that someone ate up your cake, and the subsequent conversation will be like this.

You: 내 케이크 누가 먹었어? (Who ate my cake?)
Your brother: 나는 아니야. 나는 안 먹었어. (Not me. I didn’t. )
Your mother: 미안해. 내가 먹었어. (Sorry. I ate it.)

You want to know who ate it, so you ask your family, using 누가, which is a combined word of 누구 “who” +가, the subject marker.

Then, your brother answers first, saying “Not me. I didn’t.” He uses 나는 instead of 내가, because he just wants to mention himself and insists his innocence.
So, using the topic marker, he goes, 나는 안 먹었어. “As for me, I didn’t.”

And then, your honest mother tells you that she did it, saying 내가 먹었어. (Sorry. I ate it.) Here, she uses the subject marker 가 for her answer.

It makes her, the subject of the sentence.

You can see it is more closely related to the action of eating. It sounds like “I am the right person who ate the cake.”

If she used 은/는 instead, it would sound unnatural.

In this way, you can see that there is a clear difference between the topic markers and the subject markers.

Another function of 은/는: showing contrast

Apart from the topic marking function, 은/는 also works to show some contrast between two or more things.

For example, imagine you are at a cute cafe with your friend.

You guys are happy to get to come to the new eating spot. So, the conversation will be like:

분위기가 너무 좋다. (I like the atmosphere.)
봐봐. 이 케이크도 너무 예뻐. (Look. This cake is so beautiful.)
사진도 잘 나와. (It is photogenic, too.)
근데 맛은 별로네. (But for the taste, it is just okay.)

The conversation starts with some good reactions to the cafe’s atmosphere and the beautifully decorated dessert.

When you mention the atmosphere, cake, and photos, you use the subject markers 이/가 or another particle 도, which means “too”, because sentences using those particles are neutral as an expression.

But, as you taste the cake, you unfortunately find that it is not as good as you expected based on other good factors.

Therefore, when you mention the taste, you mark it with 은 to imply that you are going to say something different.

In this way, when you say a different or opposite opinion in a context, you use 은/는 to indicate that there is something to contrast.

It is really important to note that 은/는 are used to imply something else.

So, let’s look at another example. What do you think the following sentence implies?

제 동생은 얼굴은 예뻐요.(I will tell you the meaning of each word.)

I guess quite a few Korean learners, especially beginners, will get it wrong and suppose it to be a compliment for the younger sister, saying “My sister has a pretty face.”

However, it is not. Actually, the more neutral way to give a positive description of the sister will be 제 동생은 얼굴이 예뻐요.

The difference, as you can see, is the particle marking 얼굴, face.

In both of the sentences, 제 동생은 indicates that the topic of the sentence is 제 동생, my sister, so you can tell that what is going to be talked about is the sister.

In the sentence B, it says “얼굴이 예뻐요”, which means “the face is pretty”, so the sentence B means “As for my sister, the face is pretty.”

This is a very neutral and simple compliment enough to make the sister happy.

On the other hand, in the sentence A, 은 is used to mark 얼굴.

So, the part “얼굴은 예뻐요” might imply that she certainly has a pretty face but something else about her is not as good.

It could be her short temper or inconsiderate behavior, and also it could be her poor grades. So, what sentence A implies will be something like this.

제 동생은 얼굴은 예뻐요…근데 공부도 못하고, 성격도 안 좋아요. (As for my sister, she has a pretty face, but she always gets bad grades and even has a short temper.)

Based on these examples, you can clearly see 은/는 can be used for contrast. OK?

은/는 and 이/가 in Compound Sentences

Regarding the different usage of 은/는 and 이/가, there is another important grammar rule to remember.

That is when you use them in compound sentences.

In Korean grammar, the subject in an inner clause or subordinate clause is always marked by 이/가, the subject marker.

First, please take a look at the example of an English compound sentence below.

The milk I drank was sweet.

This sentence is made up with two clauses, which have a verb in it: one is “the milk I drank” and the other is “~ was sweet”.

For the first one, which is the inner clause, the original sentence is “I drank milk.”

And for the outer structure is “The milk was sweet.” Here are the Korean translations of each sentence.

저는 우유를 먹었어요. (I drank milk.)
그 우유는 달콤했어요. (The milk was sweet.)

In these simple sentences, the subjects are marked by 은/는.

However, based on the rule I mentioned at the beginning of this section, the subject in an inner clause has to be marked by 이/가 instead of 은/는.

So, for the inner clause “the milk I drank”, you should use 제가 instead of 저는, and say “제가 먹은 우유”.

Therefore, the compound sentence in Korean will be like this:

제가 먹은 우유는 달콤했어요. (The milk I drank was sweet.)

The same rule applies to the cases where the subordinate clause is an adverb clause.

One example of an adverb clause is to express time, using when such as when I came back, or when my brother saw me and excetra. Let’s look at this sentence.

제가 집에 돌아왔을 때, 가족들은 이미 자고 있었어요.
(When I got home, my family members had already gone to bed.)

“When I got home” is the adverb clause, which is the subordinate clause of the sentence, and “my family members ~” is the main clause.

The original sentences for each clause will be these:

저는 집에 돌아왔어요. (I got home.)

그때 가족들은 이미 자고 있었어요. (At that time, my family members had gone to bed.)

Comparing them to its compound sentence, you can see the change of particles marking the subjects.

In the one-clause sentence, it is 저는, but in the subordinate clause of the compound sentence, it is 제가.

You cannot say, ”저는 집에 돌아왔을 때, 가족들은 이미 자고 있었어요.”

The only one wrong letter will make the whole sentence sound very unnatural for native speakers.

So far, we have been looking through many features about 은/는 and 이/가.

The particles work differently as a topic marker or subject marker, and because each adds different nuances of meaning to a sentence, you have to use them properly depending on the situations.


They are often mixed up by Korean learners, and it is even difficult for native speakers to explain the differences.

However, once you acquire it, you will definitely sound much more natural like native speakers.

I hope you will get a better idea from this content and become more confident in your Korean skills.

Have fun learning Korean!

그럼 오늘도 행복 가득, 웃음 가득한 하루 되세요! 한국어 화이팅, 화이팅, 화이팅!!