ellos

In a sentence

• Ellos están jugando fútbol en el parque.

  They are playing soccer in the park.

  In this sentence, 'ellos' is used as the subject pronoun to indicate who is performing the action, referring to a group of males or a mixed-gender group.

• Les dije a ellos que la reunión es mañana.

  I told them that the meeting is tomorrow.

  Here, 'ellos' functions as the object of a preposition ('a ellos'), emphasizing that the message was directed specifically to this group.

• Confiamos en que ellos sabrán qué hacer.

  We trust that they will know what to do.

  In this case, 'ellos' is also the subject pronoun of the dependent clause, again specifying the group being referred to.