The definition of an auxiliary verb is used to change the tense or voice of other verbs.
An example of an auxiliary verb is "be", "do" or "have."
Gram. a verb used to help form the tenses, aspects, voices, or moods of other verbs, as will, have, do, be, should, must
nounAbbr. aux. or aux. v.
A verb, such as have, can, or will, that accompanies the main verb in a clause and helps to make distinctions in mood, voice, aspect, and tense.
(plural auxiliary verbs)
- attributive form of auxiliary verb, noun.