What Particles (조사) Do

If Korean grammar has a beating heart, it is the particle — in Korean, 조사 (助詞). A particle is a short marker that clips onto the back of a noun and announces its job in the sentence: this noun is the subject, that one is the object, this one is the topic, that one is the place. It is the single biggest structural difference between Korean and English, and once it clicks, whole swathes of the language stop feeling random. This page introduces what particles are, why Korean needs them, and the master map of the ones you will meet first.

The core idea: roles are labeled, not positioned

English figures out who did what to whom from word order. "The dog bit the man" and "The man bit the dog" use the exact same words; only their positions differ, and that difference flips the meaning entirely. Korean does it the opposite way. Korean is an SOV language (subject–object–verb), but the particle, not the slot, is what actually assigns each noun its role.

Take a two-noun sentence:

The 가 tags 철수 as the subject (the one doing the liking); the 를 tags 영희 as the object (the one being liked). Now watch what happens when we move the nouns around:

The meaning is unchanged. 철수 still does the liking and 영희 is still liked, because 가 and 를 are welded to those nouns and travel with them wherever they go. In English, moving the nouns would swap who likes whom; in Korean, the particles hold the roles fixed no matter the order.

The proof is what happens when you swap the particles instead of the nouns:

Same word order as the first sentence, but now 영희 carries 가 and 철수 carries 를 — so the meaning flips. This is the whole principle in one comparison: in Korean, the particle decides the role; word order is free to vary for emphasis.

The master map

Particles fall into three broad families. You do not need to master them today — this is the lay of the land, and each gets its own page.

Case particles — who plays what grammatical role

Adverbial particles — where, when, how, to whom

These mark the circumstances of the action — place, time, direction, recipient.

Topic and focus particles — the discourse layer

On top of the grammatical role, Korean can flag a noun as the topic ("as for…") or add focus meanings like "also" and "only." The big one is 은/는; 도 ("also") and 만 ("only") get their own group.

The topic marker 은/는 is subtle enough — and important enough — to deserve close study; start with the topic marker 은/는 and its face-off with the subject marker 이/가.

Particles are unstressed clitics — no space, ever

A particle is not a separate word you set apart; it is a clitic that fuses onto its noun as a single spacing unit (어절). Write 책이, never ×책 이. Write 학교에서, never ×학교 에서. The particle leans on the noun the way English 's leans on a name in "Mina's" — you would never write "Mina 's."

One noun, one role — but which shape?

Most role particles come in two shapes, and which one you use depends on whether the noun ends in a consonant (a 받침, batchim) or a vowel:

• Subject: 이 after a consonant (책이), 가 after a vowel (커피가).
• Object: 을 after a consonant (밥을), 를 after a vowel (커피를).
• Topic: 은 after a consonant (책은), 는 after a vowel (저는).

This is not a meaning difference — 이 and 가 do the same job — just a sound-driven choice that keeps the language smooth. Each particle's own page lays out its allomorphs; the batchim logic behind them lives in the writing-system pages.

Here 밥 (ends in ㅂ) takes 은, and 커피 (ends in a vowel) takes 는 — the same topic marker in its two shapes.

Common Mistakes

1. Relying on word order and dropping the role particles. With both particles gone, a scrambled sentence loses its roadmap. Particles are what let Korean reorder freely, so removing them removes the safety net.

• ✗ 철수 영희 좋아해요 (who likes whom?)
• ✓ 철수가 영희를 좋아해요 — Cheolsuga Yeonghuireul joahaeyo — "Cheolsu likes Yeonghui."

2. Putting the "particle" in front, English-style. Particles are postpositions — they follow the noun.

• ✗ 에 집 있어요
• ✓ 집에 있어요 — jibe isseoyo — "I'm at home."

3. Writing a space before the particle. A particle glues to its noun as one unit.

• ✗ 학교 에서 · ✗ 책 을
• ✓ 학교에서 · ✓ 책을

4. Choosing the wrong allomorph for the noun's ending. The consonant/vowel shape has to match.

• ✗ 책가 · ✗ 커피이
• ✓ 책이 (consonant → 이) · ✓ 커피가 (vowel → 가)

5. Marking the object with the subject particle. The role has to fit the meaning — a thing being drunk is the object.

• ✗ 커피가 마셔요 (this says "coffee drinks")
• ✓ 커피를 마셔요 — keopireul masyeoyo — "I drink coffee."

Key Takeaways

• A particle (조사) clips onto the back of a noun and marks its role — subject, object, topic, place, direction, recipient.
• Korean assigns roles by particle, not position: 철수가 영희를 좋아해요 keeps its meaning even when you reorder the nouns, because 가 and 를 travel with them.
• The three families: case (이/가, 을/를, 의), adverbial (에, 에서, (으)로, 에게), and topic/focus (은/는, 도, 만).
• Particles are unstressed clitics — never a space before them (책이, not ×책 이).
• Most come in two shapes chosen by the noun's final sound (책이 / 커피가) — same job, different form.