Give Formal Commands Using usted/ustedes

For -ar verbs, take the yo form of the verb and change the ending to -e.
Ex: siento becomes siente.
No siente al niño delante de la televisión.
Don't sit the child in front of the television.

For -er and -ir verbs, take the yo form of the verb and change the ending to -ar.
Ex: como becomes coma
Coma comidas nutritivas.
Eat nutritious foods.

For ustedes commands, use plural endings.
Ex: hablo becomes hablen
Hablen español, por favor.
Speak spanish, por favor.

Some common verbs have irregular usted commands.
dar: dé; den
estar: esté; estén
ir: vaya; vayan
saber: sepa; sepan
ser: sea; sean

Don't forget that -go verbs will have the spelling change in them! Ex; poner - pongo - ponga.