The Basics: Particles (Part 1)

The subject, object, and topic markers, plus the three particles that tell you where something is happening.

You can know a thousand Korean words and still not be able to say a sentence, because words alone don’t tell you who’s doing what to whom. That job belongs to particles: small syllables attached to the end of a word that mark its role in the sentence. English does this with word order. Korean does it with particles, which is exactly why word order in Korean is so much more flexible than it is in English. Does your native language have a flexible word order as well?

This post covers the first five you’ll use in almost every sentence: the subject marker, the object marker, the topic marker, and the two most common location particles.

The subject particle: -이/가

This marks who or what is doing the action, or who or what a description applies to. Use -가 after a vowel, -이 after a consonant.

고양이가 자요. = The cat is sleeping.
학생이 질문해요. = The student is asking a question.

It’s easy to assume this is just “the word for the subject,” but its real job is narrower: it introduces new or specific information, or answers the question “who/what?” That distinction matters more once you meet -은/는 below.

The object particle: -을/를

This marks what’s receiving the action, the thing the verb is being done to. Use -를 after a vowel, -을 after a consonant.

밥을 먹어요. = I’m eating rice.
영화를 봤어요. = I watched a movie.

If a verb has a direct object in English, that object almost always needs -을/를 in Korean, even in casual speech where other particles sometimes get dropped.

Notice: If you have the eyes of a detective, you might have noticed that the subject has been omitted. When the context makes it obvious who we're talking about, Koreans often omit the subject altogether. Depending on the context, that same sentence could technically mean you watched a movie, she watched a movie, he watched a movie, etc.

The topic particle: -은/는

This is where most learners get stuck, because -은/는 and -이/가 both get glossed as “the subject” in early textbooks. They’re not interchangeable. -는 (after a vowel) and -은 (after a consonant) mark what the sentence is about, not necessarily who’s doing the action.

저는 학생이에요. = I’m a student. Literally: As for me, I’m a student.
오늘은 바빠요. = As for today, I’m busy.

A useful rough test: if you could naturally say “as for ___” in English, -은/는 usually fits. -이/가 tends to show up when you’re introducing something for the first time or singling it out; -은/는 tends to show up when you’re talking about something already on the table, or contrasting it with something else.

저는 학생이에요. 제 친구는 회사원이에요. = I’m a student. My friend, on the other hand, is an office worker.

Notice how -는 in the second sentence sets up a contrast. That’s a job -이/가 can’t do.

Location and direction: -에, -에서, -(으)로

These three get mixed up constantly because they can all translate to “at,” “in,” or “to” depending on the sentence. Each one actually has a specific job.

-에 marks a location where something exists, or a destination with movement verbs.

집에 있어요. = I’m at home.
학교에 가요. = I’m going to school.

-에서 marks the location where an action happens, not just exists.

카페에서 커피를 마셔요. = I’m drinking coffee at the cafe.
도서관에서 공부해요. = I’m studying at the library.

The difference is simple once you see it side by side: 집에 있어요 (I’m home. Literally: I exist at home) versus 집에서 자요 (I sleep at home (an action)). If a verb describes something happening, not just something being located somewhere, -에서 is usually the right choice.

-(으)로 marks direction, method, or means. Use -로 after a vowel or ㄹ, -으로 after other consonants.

오른쪽으로 가세요. = Go to the right.
버스로 가요. = I’m going by bus.
손으로 써요. = I’m writing by hand.

Why this is worth drilling before anything else

Particles are unglamorous. There’s no dramatic “aha” moment the way there can be with vocabulary or culture notes. But they’re the connective tissue that makes every other word in a sentence make sense, and getting -이/가 and -은/는 backwards is one of the fastest ways to sound like you’re translating from English word by word.

The fix is your choice. Some people opt for doing more particle drills until they memorize. Personally, I like using them out loud, in full sentences, until choosing the right one stops being a conscious decision. 30 Days of Korean Speaking gives you a new scenario every day built around exactly that kind of live, unscripted production, so particles like these get practiced the way you’ll actually need them: in the moment, not on a worksheet.

For sentence-level practice that forces you to use particles in real time, check out How to Practice Korean Speaking Alone. Especially the roleplay and self-talk methods.

Part 2 of this series covers -도, -만, -까지, -부터, and the comparison particles -보다, -처럼, and -같이.