Auxiliary verbs are helper verbs. They work with a main verb or stand before a subject. In this module, the main auxiliary verbs are be, do, and have. They help make negatives, questions, and some tense forms.

The auxiliary verb be changes with the subject. In the present, it is am, is, or are. In the past, it is was or were. Be is also an auxiliary in continuous forms.

Subject	Form
I	am
he	is
she	is
it	is
you	are
we	are
they	are
I	was
he	was
she	was
it	was
you	were
we	were
they	were

Use be with the -ing form to make the present continuous. This form shows an action happening now or around now. The auxiliary comes before the main verb.

Use do and does to make present simple questions. Use do with I, you, we, and they. Use does with he, she, and it. The main verb stays in the base form.

Subject	Form
I	do
you	do
we	do
they	do
he	does
she	does
it	does

Use do not and does not to make present simple negatives. Do not goes with I, you, we, and they. Does not goes with he, she, and it. The main verb stays in the base form after the auxiliary.

Use did to make past simple questions and negatives. Did works with all subjects. The main verb stays in the base form after did or did not.

Subject	Form
I	did
you	did
he	did
she	did
it	did
we	did
they	did

Use have and has as auxiliary verbs in basic perfect forms. Use have with I, you, we, and they. Use has with he, she, and it. The main verb uses the past participle after the auxiliary.

Subject	Form
I	have
you	have
we	have
they	have
he	has
she	has
it	has

The auxiliary have or has comes before the past participle in a basic perfect form. This form connects a past action to now. The auxiliary shows the subject, and the participle stays the same for all subjects.

You can now choose be, do, did, have, and has as auxiliary verbs. You can use them to build basic negatives, questions, the present continuous, and basic perfect forms. You can also match each auxiliary verb to the correct subject and keep the main verb in the correct form.