Expressing possibility, ability, permission, advice, and obligation in English
The modal and other auxiliary verbs are sometimes called "helping verbs." Helping verbs are the verbs that help other verbs work. Helping verbs typically help express grammatical tense, aspect, mood, and voice.
The helping verbs in alphabetical order: be, can, could, dare, do, have, *have to, may, might, must, *need to, *ought to, shall, should, *used to, will, and would.
[*special forms requiring "to"]
Forming Statements Using Helping Verbs
Here are present tense patterns and some examples:
In Active Voice
There are three forms: simple, simple progressive, and compound
Simple: Subject + helping + Verb 2 + the rest.
Vacations can relieve stress.
Vacations + can + relieve + stress.
Simple progressive (always with "be"):
Subject + be+ verb 2 progressive + verb 3 progressive the rest.
I am enjoying singing for you.
I + am + enjoying + singing + for you.
Subject + helping + verb 2 participle + verb 3 progressive + the rest.
We have enjoyed singing for you.
We + have + enjoyed + singing + for + you.
In Passive Voice (always with "be")
There are two forms: simple and compound.
Formula 1: Simple