Between sentences
| 그리고 | and (then) |
| 그래서 | so, therefore |
| 그런데 | but, by the way |
| 하지만 / 그렇지만 | but, however |
| 그러면 / 그럼 | then, in that case |
Inside one sentence
- -고 — and (listing, or sequence): 밥을 먹*고 커피를 마셔요.*
- -아서/어서 — because / and then (linked actions): 배가 고*파서 밥을 먹었어요.* 학교에 가*서 공부해요* (go to school and study there).
-아서/어서 never takes the past tense itself; the final verb carries the tense: 갔어서 → 가서.
It also can't be used with commands or suggestions ("because it's cold, let's …" uses -(으)니까, see B1).