Understanding Korean Particles: 은/는 vs 이/가

If you've been studying Korean for a while, you've probably stumbled on this question: when do I use 은/는 and when do I use 이/가?

You're not alone. This is one of the most commonly asked questions by Korean learners.

The Short Answer

• 은/는 = Topic marker ("As for X...")
• 이/가 = Subject marker ("X does something")

은/는 — Topic Particle

Use 은 after a consonant, 는 after a vowel.

This particle marks the topic of the sentence — what you're talking about.

저는 학생이에요. jeoneun haksaengieyo "(As for me,) I am a student."

한국어는 재미있어요. hangugeo-neun jaemiisseoyo "(As for Korean,) it's fun."

이/가 — Subject Particle

Use 이 after a consonant, 가 after a vowel.

This particle marks the subject — who or what is performing the action.

비가 와요. biga wayo "Rain is falling." (It's raining.)

고양이가 귀여워요. goyangi-ga gwiyeowoyo "The cat is cute."

When to Use Which?

New vs Known Information

• 이/가 introduces new information
• 은/는 refers to already known information

A: 누가 왔어요? (Who came?) B: 민수가 왔어요. (Minsu came.) — new info → 이/가

A: 민수는 어디 있어요? (Where is Minsu?) — known topic → 은/는

Contrast

은/는 is also used for contrast:

커피는 좋아해요, 차는 안 좋아해요. "I like coffee, but I don't like tea."

Practice Tip

Don't overthink it at first. Start by defaulting to 은/는 for the topic of your sentence, and use 이/가 when answering "who?" or "what?" questions. Over time, it becomes natural!

화이팅! (You can do it!)