This document discusses the formation of formal commands (Ud. and Uds.) in Spanish. It explains that formal commands use the same spelling changes as informal negative commands. For -ar verbs, add -e or -en; for -er verbs, add -a or -an; and for -ir verbs, add -a or -an. Pronouns can be attached to affirmative commands or placed before the verb for negative commands. Irregular formal commands like saber, dar, estar, ir, and ser are also listed.