Dictionary
auxil'iary verb'
a word used in construction with and preceding certain forms of other verbs, as infinitives or participles, to express distinctions of tense, aspect, mood, etc., as
did in
Did you go?, am in
I am listening, have in
We have spoken, or
can in
They can see. Also called
helping verb. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.