너희 썸 타?

The line, explained

Two characters keep 'accidentally' sitting together, texting late at night, and buying each other coffee. Then their best friend narrows their eyes and asks: 너희 썸 타? Are you two a thing? Both of them immediately say no, a little too loudly. 썸 is one of the most useful pieces of modern Korean slang, because it names a stage English never quite found a word for.

썸 comes from the English word some, as in something. It describes the time when two people clearly like each other, flirt, and spend time together, but have not made it official. Not friends, not dating, just something. It is the stage of butterflies and overthinking every text, which is why Korean dramas can stretch it across eight episodes. Koreans even joke that 썸 is the best part of a relationship.

The fun part is the verb. You don't have or do a 썸. You ride it: 썸 타다, with 타다 meaning to ride, the same verb used for buses, bikes and roller coasters. The image fits perfectly, because the stage feels like a ride with ups and downs. In this line, 타 is 타다 in casual form, and the rising tone makes it a question.

너희 means you guys or you two, the plural of casual 너. It is spelled 너희 but most people pronounce it close to neo-hi. Use it with friends, never with elders. You will also hear 썸남, the guy you are in a 썸 with, and 썸녀, the girl. To say who you are in it with, use 랑: 걔랑 썸 타 means I'm in a thing with them.

Once it is official, you stop riding 썸 and start 사귀다, to date. The polite answer to this teasing question is 아니야! (no!), usually followed by a blush that says yes. Try swapping who is being teased: 둘이 썸 타? means are the two of you a thing, and 우리 썸 타? is the brave question you ask the person directly.