Auxiliary verbs are used together with a main verb to give grammatical information and therefore add extra meaning
to a sentence. Information that is not given by the main verb.
They are used to form the passive voice.
They are used to form the continuous tense.
They are used to form the perfect tense.
Be, Do and Have are auxiliary verbs, they are irregular verbs
and can be used
as main verbs. The verbs 'to be' and 'to have' are the most
commonly used auxiliary verbs and work alongside the main verbs in
any statement.
Modal verbs are also auxiliary verbs,
but will be treated separately, these are can, could, may, might, must,
shall, should, will, and would, they differ from the others in that they can never function as a main verb.
To be
Be is the most common verb in the English language. It can be used as
an auxiliary and a main verb. It is used a lot in its other forms.
Base form = be
Present form = am/is/are
Past form = was/were
Present Participle / Gerund = being
Past Participle = been
To do
The verb do is one of the most common verbs in English. It can be used
as an auxiliary and a main verb. It is often used in questions.
Base form = do
Present form = do/does
Past form = did
Present Participle / Gerund = doing
Past Participle = done
To have
Have is one of the most common verbs in the English language.
Base form = have
Present form = have / has
Past form = had
Present Participle / Gerund = having
Past Participle = had