선원들이

sailors

→ 선원
phrase Rare #18,099
sailors 들 marks the noun as plural, and 이 marks it as the subject of the sentence.
KO: 선원들이 배를 준비했어요.
EN: The sailors prepared the boat.

여동생은 선원들이 붙인 농담 섞인 별명 이었다.

“Little sister” was a teasing nickname the sailors had given her.

하지만 선원들이 일을 정확히 해내야 했다.

But the sailors had to do their jobs properly.