Auxiliary verbs are commonly referred to as
"helping" verbs. They add detail to the main verbs. Some common
auxiliary verbs are: be, been, is, are, was, were, will, can, has, have, had,
do, does, did, could, should, would. For example, consider the following sentence:
Emma could have run the race
a lot faster; she might have won first place.
Here, "could", "might", and
"have" are the auxiliary verbs.