Korean grammar uses particles to mark roles in a sentence, and the two most confusing ones for learners are 은/는 and 이/가. 🌀 These are the topic and subject markers, and while they may seem interchangeable at first, they actually serve distinct purposes in Korean communication.
Understanding when to use 은/는 vs. 이/가 will make your Korean sound more natural and native-like. It also helps you understand conversations better, especially when emphasis or nuance is involved.
📘 What Are 은/는 and 이/가?
은/는 is called the “topic particle.” It marks the main idea or what the sentence is about. 이/가 is called the “subject particle.” It marks the grammatical subject, the noun that performs the action or is described.
These particles attach to nouns based on whether the noun ends in a consonant or a vowel:
- 은 – used after a consonant (e.g., 책은)
- 는 – used after a vowel (e.g., 사과는)
- 이 – used after a consonant (e.g., 학생이)
- 가 – used after a vowel (e.g., 나가)
📊 Particle Type Table
| Particle | Attached To | Example |
|---|---|---|
| 은 | Nouns ending in consonant | 책은 좋아요 |
| 는 | Nouns ending in vowel | 사과는 맛있어요 |
| 이 | Nouns ending in consonant | 학생이 왔어요 |
| 가 | Nouns ending in vowel | 나가 말했어요 |
🔍 Core Differences Between Topic and Subject
Here’s where things get interesting. While both particles mark a noun, they serve different roles. 은/는 sets the stage—it introduces or contrasts. 이/가 tells you who or what is doing the action.
If you're introducing a new subject in the conversation, you’ll likely use 이/가. If you're comparing or shifting topics, 은/는 makes more sense.
📊 Core Function Table
| Particle | Function | When to Use |
|---|---|---|
| 은/는 | Topic marker | To contrast, compare, or set the scene |
| 이/가 | Subject marker | To introduce a new subject or emphasize who did what |
🎯 Emphasis & Focus: What’s Being Highlighted?
One of the key differences between 은/는 and 이/가 lies in what they emphasize. When you use 은/는, you’re typically highlighting the **topic** of the sentence or contrasting it with something else.
On the other hand, 이/가 brings focus to the **subject itself**, often introducing new information or emphasizing who or what is performing an action.
Think of 은/는 like zooming out to show the big picture (theme), while 이/가 zooms in on the performer or cause of an action.
📊 Emphasis Comparison Table
| Sentence | Focus | Explanation |
|---|---|---|
| 나는 학생이에요 | Topic: 나 | “As for me, I am a student” |
| 내가 학생이에요 | Subject: 나 | “I (not someone else) am the student” |
🧠 Choosing the Right Particle Based on Context
Knowing the grammar is one thing, but using particles correctly in actual conversations depends heavily on context.
Use 은/는 when:
- 🔄 You’re contrasting two things
- 🎬 Introducing a general topic or background
- 🔊 Talking about something already known
Use 이/가 when:
- 🆕 Introducing new information or people
- 🎯 Emphasizing the doer of an action
- 🤔 Answering questions like “Who did it?”
📊 Contextual Usage Table
| Context | Use | Example |
|---|---|---|
| Topic Introduction | 은/는 | 오늘은 날씨가 좋아요 |
| New Subject | 이/가 | 친구가 왔어요 |
📊 Comparison Table with Examples
Here's a side-by-side view to summarize everything clearly. This table will help you decide which particle fits best in real-world usage.
📊 Final Comparison Table
| Use Case | 은/는 | 이/가 |
|---|---|---|
| Focus | Topic (theme, contrast) | Subject (doer, new info) |
| Common Function | Set the context | Deliver new details |
| Example | 저는 학생이에요 | 제가 학생이에요 |
✏️ Practice Sentences
Here are some useful sentence pairs. Try reading them aloud and feel the nuance shift depending on the particle!
📊 Practice Sentences Table
| Sentence with 은/는 | Sentence with 이/가 | Meaning Shift |
|---|---|---|
| 철수는 학교에 갔어요 | 철수가 학교에 갔어요 | Topic vs. emphasis on subject |
| 오늘은 날씨가 좋아요 | 오늘이 날씨가 좋아요 | General vs. focused info |
❓ FAQ
Q1. Are 은/는 and 이/가 interchangeable?
A1. They may seem interchangeable at times, but they carry different meanings. 은/는 marks the topic and gives background or contrast, while 이/가 focuses on the subject performing the action.
Q2. How can I tell which one to use in a sentence?
A2. Ask yourself: am I introducing a new subject (use 이/가), or am I contrasting or giving context (use 은/는)? That’ll usually guide your choice correctly.
Q3. Is one more formal than the other?
A3. No, both are neutral in formality. The choice between them depends on sentence role, not tone or politeness level.
Q4. Can both particles appear in one sentence?
A4. Yes! You can often see sentences like “오늘은 날씨가 좋아요,” where 오늘은 is the topic and 날씨가 is the subject. This combination is very natural in Korean.
Q5. What happens if I use the wrong one?
A5. Your sentence might still be grammatically correct, but the meaning or emphasis could shift. Native speakers might notice the nuance is off.
Q6. Should beginners focus on just one particle first?
A6. That can help. Start with 은/는 to get used to setting sentence topics. Then gradually add 이/가 as you learn to express subjects and actions with nuance.
Q7. Does spoken Korean always follow the particle rules?
A7. Mostly yes, but particles are sometimes dropped in casual speech when the meaning is obvious. Still, they’re crucial for clarity, especially in writing and formal conversation.
Q8. I hear “내가” a lot in K-dramas. Why?
A8. “내가” (I + subject marker) is often used to emphasize that “I” did something—especially in emotional or dramatic situations. It shows ownership and focus on the subject.
Disclaimer: The explanations in this post are intended for beginner-to-intermediate learners. Korean is a context-heavy language, and particle use may vary by region, tone, and formality. Always consult with native speakers or verified learning materials when studying for formal purposes.
