들

In a sentence

• 학생들께서 교실에 들어왔습니다.

  The students came into the classroom.

  Here, '들' is attached to the word '학생' (students) to indicate plurality, denoting multiple students.

• 책이들 몇 권 테이블에 놓여 있습니다.

  There are a few books placed on the table.

  In this sentence, '들' follows '책' (book), signifying plural form to refer to multiple books in general usage.

• 하늘을 바라보면 새들이 날고 있어요.

  When you look at the sky, birds are flying.

  Here, '들' is used with '새' (bird) to indicate plural, suggesting the presence of many birds flying in the sky.