Formal Commands

To form a FORMAL command in Spanish:
Find the INFINITIVE verb you would like to use.
Infinitive verbs end in -AR/-ER/-IR
Doblar = to talk
Comer = to eat
Vivir = to live
For AR verbs:
Remove the -AR and add an "e"
Hable con su doctor. = Talk with your doctor
For ER and IR verbs:
Remove\ the ER and add an "a"
Coma más verduras. = Eat more vegetables.
For IR verbs:
Remove the IR and add an "a"
Viva en paz. = Live in peace.

In order to command a group using formal commands, make the same changes to the verb and add an "n".
Hablen con su doctor. = Talk with your doctor.

https://studyspanish.com/grammar/lessons/formcomm