Korean Particles 은/는 vs 이/가

The Fast Difference

Use 은/는 when you want to set the frame of the sentence. It often means as for this thing or speaking of this person. Use 이/가 when you want to identify who or what fits the sentence, especially when the information is new or important.

For example, 저는 학생이에요 means as for me, I am a student. 제가 학생이에요 can answer who is the student? The English translation may look similar, but the Korean information focus is different.

• 은/는 = topic, contrast, general frame
• 이/가 = subject, identification, new information
• English translation alone cannot decide the particle

When to Use 은/는

은/는 is useful when a noun is already the topic or when you are making a general statement about it. 한국어는 재미있어요 means Korean is interesting, with Korean as the topic. 저는 미국에서 왔어요 means as for me, I came from the United States.

은/는 also creates contrast. 커피는 좋아해요 can mean I like coffee, but it may imply contrast with something else: I like coffee, but maybe not tea. This contrast feeling is one reason 은/는 appears often in comparisons.

• 저는 학생이에요 = As for me, I am a student.
• 한국어는 재미있어요 = Korean is interesting.
• 커피는 좋아해요 = I like coffee, with possible contrast.

When to Use 이/가

이/가 marks the subject that is being identified or focused. If someone asks 누가 왔어요? meaning who came?, the natural answer is 친구가 왔어요. The new important information is 친구, so 가 fits.

이/가 is also common with 있다, 없다, 좋다, 많다, and descriptions where the subject is being presented. 시간이 없어요 means there is no time. 날씨가 좋아요 means the weather is good.

• 친구가 왔어요 = A friend came.
• 시간이 없어요 = There is no time.
• 날씨가 좋아요 = The weather is good.

Consonant and Vowel Forms

The particle form changes based on the final sound of the noun. Use 은 after a consonant and 는 after a vowel. Use 이 after a consonant and 가 after a vowel. This is a sound rule, not a meaning rule.

For example, 학생 ends in a consonant, so 학생은 and 학생이 are possible forms. 저는 uses 는 because 저 ends in a vowel. 친구가 uses 가 because 친구 ends in a vowel.

• Consonant + 은: 학생은
• Vowel + 는: 저는
• Consonant + 이: 학생이
• Vowel + 가: 친구가

Topic vs New Information

A helpful question is: does the listener already know what I am talking about? If the noun is the frame of the conversation, 은/는 often works. If the noun is the new answer or the thing being identified, 이/가 often works.

Compare 이 식당은 맛있어요 and 이 식당이 맛있어요. The first sets this restaurant as the topic: as for this restaurant, it is good. The second can identify this restaurant as the good one, especially among choices.

• Known topic: 은/는
• New answer: 이/가
• Choice or identification: often 이/가

Mini Practice

Choose the better particle based on the situation. If someone asks who is Korean?, answer 제가 한국 사람이에요. If you are introducing yourself generally, say 저는 한국 사람이에요. If you contrast coffee with tea, 커피는 좋아해요 sounds natural.

Now fill in the blanks: 저는 학생이에요. 친구가 왔어요. 시간이 없어요. 한국어는 재미있어요. Read each sentence aloud and ask whether the noun is a topic, contrast, or focused subject.

• General self-introduction: 저는
• Who answer: 제가
• There is no time: 시간이
• Korean as a topic: 한국어는

What is the difference between 은/는 and 이/가?

은/는 marks a topic or contrast, while 이/가 marks a focused subject, new information, or identification.

Should I say 저는 or 제가?

Use 저는 for a general self-introduction or topic. Use 제가 when answering who? or focusing I as the subject.

Can 은/는 and 이/가 both be correct?

Yes. Sometimes both are grammatical, but they usually create a different focus or nuance.

How do I choose 은 or 는?

Use 은 after a consonant-ending noun and 는 after a vowel-ending noun.