I will tell him/her/you
Le contaré todo a mamá cuando vuelva.
I'll tell Mom everything when I get back.
— Jojo Rabbit (2019)
I'll tell you a secret.
Le contaré otro cuento de niños.
I'll tell you another children's story.
— Indiana Jones y la última cruzada (1989)
Y luego le contaré lo que sucede arriba.
And then I'll tell you what's happening upstairs.
— Parásitos (2019)
I'll tell you my story.
Ahora iré a casa y le contaré.
Now I'll go home and tell him.
I’ll tell you a story.