The most common auxiliary verbs are "be," "do," and "have", and you may also use these verbs on their own. Other common auxiliaries are "can," "could," "may," "might," "must," "ought," "should," "will," and "would."
there are some auxiliary verbs that are use in pairs e.g. can/could, may/might, shall/should, will/would, must, ought to and dare.