Formal Commands

When you are directly addressing a person or persons that you would normally address as usted or ustedes, give formal commands by taking the yo form of the present indicative tense and changing the ending of -ar verbs to -e for singular (usted) commands or -en for plural (ustedes) commands and changing the ending of -er/-ir verbs to -a or -an. Because you are working from the yo form of the present indicative, the formal commands reflect the irregularities you find in irregular and stem-changing verbs.

Regular Verbs

-AR
buscar > busque, busquen*
dejar > deje, dejen
hablar > hable, hablen
llamar > llame, llamen
 
-ER/-IR
comer > coma, coman
insistir > insista, insistan
leer > lea, lean
vivir > viva, vivan

Verbs with Irregular yo Forms

conocer (conozco) > conozca, conozcan
decir (digo) > diga, digan
oír (oigo) > oiga, oigan
poner (pongo) > ponga, pongan
salir (salgo) > salga, salgan
tener (tengo) > tenga, tengan
traer (traigo) > traiga, traigan
venir (vengo) > venga, vengan

Stem-Changing Verbs

almorzar (ue) > almuerce, almuercen*
cerrar (ie) > cierre, cierren
empezar (ie) > empiece, empiecen
jugar ( ue) > juegue, jueguen*
pedir (i) > pida, pidan
perder (ie) > pierda, pierdan
servir (i) > sirva, sirvan
volver (ue) > vuelva, vuelvan

*NOTE: A spelling change is necessary to preserve the sound of the infinitives that end in -car, -gar, and -zar: c > qu, g > gu, and z > c.

A few verbs have irregular command forms and must be memorized:

dar > dé, den
estar > esté, estén
ir > vaya, vayan
saber > sepa, sepan
ser > sea, sean