Use this section for verbal auxiliaries, affixes, adverbs, and particles that indicate imperatives. The following definitions are taken from Bybee, Joan, Revere Perkins, and William Pagliuca. 1994. The evolution of grammar. Chicago and London: University of Chicago Press. Use this domain for words and affixes that a speaker uses to indicate that he is making a command. English has no command word. Some languages change the form of the verb by adding an affix. Some languages have special verbs that are only or normally used as commands. Those verbs could be classified here.