Answer:
Affirmative formal commands to tell your best friend what to do:
¡Compre el libro!
Buy the book!
Negative formal commands to tell your best friend what not to do.
No se atreva a ir a la fiesta sin mí!
Don't you dare go to the party without me.
Doler with a negative formal command to keep your best friend from getting worse.
No dejes que te duela el estómago por beber café.
Don't let your stomach hurt because of drinking coffee.
An affirmative formal command to tell your best friend how to take care of himself while at home.
Beba té y miel para curarte la garganta.
Drink tea and honey to cure your sore throat.
Regular and/or stem-changing verbs.
at least one body part
¿Siente dolor en el estómago?
Do you feel pain in your stomach?
