1. Usted/Ustedes Commands; Pronoun Placement with Commands
Unidad 5 Lección 1

2. Usted/Ustedes Commands
To form the usted command:
start with the yo form of the verb in present
drop the o, then add the opposite “theme” vowel
probar  yo pruebo  pruebe(n)
comer  yo como  coma(n)
añadir  yo añado  añada(n)
Add no before the verb to make commands negative.

3. Irregular usted/ustedes commands
dar dé den
ir vaya vayan
ser sea sean
haber haya hayan
estar esté estén
saber sepa sepan

4. Verbs ending in -car, -gar, -zar have a spelling change in the command form:
buscar  busque(n)
pagar  pague(n)
empezar  empiece(n)

5. Pronoun Placement with Commands
In affirmative commands, attach the object pronouns to the verb.
Llévenos al supermercado.
In negative commands, place the object pronouns before the verb.
No lo prueben.