게 흘러가다

how it flows or unfolds

흘러가다 is literally flowing, and every line here uses it for time, a conversation or a situation going along. 순조롭게 흘러가다 and 순탄하게 흘러가다 both mean "going smoothly, no snags"; 편하게 흘러가다 is a conversation flowing comfortably. 어떻게 흘러가는지 — "how it's going" — appears three times, including 하루가 어떻게 흘러가는지 모르겠어, "I don't know where the day goes". For water actually flowing, the same verb is used unchanged.