는데: But, and, so (background)

(으)ㄴ데 / 는데: the most useful ending nobody teaches first

If you learn one connector beyond "and" and "but", make it this one. 는데 is everywhere in spoken Korean, and textbooks tend to file it under "but", which is the least interesting thing it does.

Attaching it

• Verbs: stem + 는데. 가는데 ganeunde, 먹는데 meongneunde
• Adjectives: stem + (으)ㄴ데. 예쁜데 yeppeunde, 좋은데 joeunde. Exception: 있다/없다 and words built on them take 는데, so 없는데 eomneunde, 재미있는데 jaemiinneunde
• Nouns: noun + 인데 inde. 학생인데 haksaeng-inde
• Past tense: always 았/었는데 anneunde/eonneunde, for verbs and adjectives alike. 갔는데 ganneunde, 좋았는데 joanneunde

The past-tense line is the one to hold onto: the verb-versus-adjective split disappears once you're in the past.

Job one: setting something up

This is the use that matters most and the one "but" completely fails to capture. 는데 hands the listener background before the real point arrives.

• 어제 영화를 봤는데 정말 재미있었어요. eoje yeonghwa-reul bwanneunde jeongmal jaemiisseosseoyo — "I saw a movie yesterday, and it was really good."

There's no contrast there at all. It's "here's the setup, now here's the thing".

Job two: contrast

• 형은 키가 큰데 저는 작아요. hyeong-eun ki-ga keunde jeoneun jagayo — "My brother is tall, but I'm short."

This is the textbook meaning, and it's maybe a third of the actual usage.

Job three: softening

Korean uses 는데 to take the edge off a request, the way English pads things with "I was wondering if".

• 좀 바쁜데 도와주실래요? jom bappeunde dowajusillaeyo? — "I'm a bit busy — could you help me?"

Job four: trailing off on purpose

You can end a sentence on 는데 and simply stop. It isn't an unfinished thought; it's a deliberate one.

• 시간이 없는데 sigani eomneunde... sigan-i eomneunde... — "It's just that I don't have time..."

Leaving it hanging lets the listener draw the conclusion, which is softer than stating it. Refusals, complaints and hints all lean on this. Once you notice it you'll hear it constantly.

Why it's worth the trouble

는데 is doing pragmatic work, not just logical work. It manages how blunt you sound. That's why a sentence can be grammatically perfect and still land wrong without it, and why fluent-sounding speech is full of 는데 where a textbook would use a full stop.

는데 vs 지만

Both can mean "but". 지만 jiman is a clean, clear contrast, and that's all it does. 는데 neunde is softer and can also just mean "and" or set up background.

• 이 식당은 비싸지만 맛있어요. i sikdangeun bissajiman masisseoyo "This place is expensive, but it's good."
• 이 식당은 비싼데 맛있어요. i sikdangeun bissande masisseoyo Same idea, more relaxed and chatty.

When you want a sharp contrast, or you're writing something formal, 지만 jiman is the safer pick. In casual speech, 는데 neunde is far more common.

Questions with 는데?

In casual speech, a question can end on 는데? neunde. It asks for the missing piece, often with a hint of "so what's the deal?":

• 어디 가는데? eodi ganeunde "So where are you going?"
• 그래서 뭐 하자는 건데? geuraeseo mwo hajaneun geonde "So what are you saying we should do?"

Said with a flat tone, it can sound a bit challenging, so it's best kept for friends.