they cheered up, they made (someone) happy
Todos se alegraron.
Everyone was happy.
Me alegraron el día.
They made my day.
— Jojo Rabbit (2019)
Los estudiantes alegraron su vida.
The students brightened his life.
Ellos se alegraron por el nacimiento de su primer hijo.
They rejoiced at the birth of their first child.
Se alegraron cuando se enteraron que estaba a salvo.
They were happy when they learned that he was safe.