From Longman Dictionary of Contemporary Englishauxiliary verbauxˌiliary ˈverb noun [countable] SLGa verb that is used with another verb to show its tense, person, mood etc. In English the auxiliary verbs are ‘be’, ‘do’, and ‘have’ (as in ‘I am running’, ‘I didn’t go’, ‘they have gone’), and all the modals.
