Old News, New News 은/는 vs 이/가

Point out the cat everyone already knows: 고양이는 귀여워요. Then announce that there’s a cat in the room: 고양이가 있어요. 은/는 frames a topic; 이/가 marks a subject, often when it is new or the point of the sentence.

Introducing vs. Commenting

Answering “Who”

Question words like 누구 (who) almost always pull 이/가, because the answer is by definition new information. 누구 even contracts with 가 irregularly, dropping a syllable: 누구가 becomes 누가.

Swap that same sentence to 는 and the meaning shifts. 안나 씨는 선생님이에요 doesn’t answer “who’s the teacher,” it responds to something like “what does Anna do?” Anna is already the topic; her job is the new part.

Contrast

는 has a second job that has nothing to do with old versus new information: setting up a contrast between two things.

One Common Mix-Up

좋아하다 (to like, an action) and 좋다 (to be good, a description) look related and get confused constantly, but they don’t take the same particle. 좋아하다 acts like an ordinary verb and takes 을/를 on what you like, exactly like 커피를 좋아해요 above. 좋다 describes a quality instead of naming an action, so whatever’s pleasing takes 이/가, the same particle that’s been marking the subject in every example above.

Vocabulary