The Auxiliary Verb
Recognize an auxiliary verb when you see one.
Sometimes an action or condition occurs just once—bang!—and it's over.
Nate stubbed his toe.
He is miserable with pain.
Other times, the activity or condition continues over a long stretch of time, happens predictably, or occurs in relationship to other events. In these instances, a single-word verb like stubbed or is cannot accurately describe what happened, so writers use multipart verb phrases to communicate what they mean. As many as four words can comprise a verb phrase.
A main or base verb indicates the type of action or condition, and auxiliary—or helping—verbs convey the other nuances that writers want to express.
Read these three examples:
Sherylee smacked her lips as raspberry jelly dripped from the donut onto her white shirt.
Sherylee is always dripping something.
Since Sherylee is such a klutz, she should have been eating a cake donut, which would not have stained her shirt.
In the first sentence, smacked and dripped, single-word verbs, describe the quick actions of both Sherylee and the raspberry jelly.
Since Sherylee has a pattern of messiness, is dripping communicates the frequency of her clumsiness. The auxiliary verbs that comprise should have been eating and would have stained express not only time relationships but also evaluation of Sherylee's actions.
Below are the auxiliary verbs. You can conjugate be, do, and have; the modal auxiliaries, however, never change form.
Be Do Have am
Modal Auxiliaries [Never Change Form] can, could, may, might, must, ought to, shall, should, will, would
Understand the dual nature of be, do, and have.
Be, do, and have are both stand-alone verbs and auxiliary verbs. When these verbs are auxiliary, you will find them teamed with other verbs to complete the verb phrase. Compare these sentences:
Freddy is envious of Beatrice’s steaming bowl of squid eyeball stew.
Is = linking verb.
Freddy is studying Beatrice’s steaming bowl of squid eyeball stew with envy in his eyes.
Is = auxiliary verb; studying = present participle completing the verb phrase.
We did our homework for Mrs. Long.
Did = action verb.
We’re not slackers! We did prepare our homework for Mrs. Long.
Did = auxiliary verb; prepare = main verb completing the verb phrase.
Selena has twelve orange goldfish in her aquarium.
Has = action verb.
Selena has bought a catfish to help keep the tank clean.
Has = auxiliary verb; bought = past participle completing the verb phrase.
Form progressive tenses with the auxiliary verb be.
All progressive tenses use a form of be. Present progressive follows this pattern:
am, is, or are + present participle
Use the present progressive tense to convey an action or condition happening right now or frequently.
I am baking chocolate-broccoli muffins today.
Am = auxiliary verb; baking = present participle completing the verb phrase.
Alex is sitting at the kitchen table, anticipating his first bite.
Is = auxiliary verb; sitting = present participle completing the verb phrase.
Alex must wait a while longer because the muffins are cooling by the window.
Are = auxiliary verb; cooling = present participle completing the verb phrase.
Impatient Alex is always waiting to taste whatever I cook.
Is = auxiliary verb; waiting = present participle completing the verb phrase.
Past progressive follows this pattern:
was or were + present participle
Use the past progressive tense to show either 1) an action or condition that continued in the past or 2) an action or condition interrupted by another.
Naomi was hoping for an A in her organic chemistry class.
Was = auxiliary verb; hoping = present participle completing the verb phrase.
Unfortunately, Naomi's lab reports were missing the nutritional data on chocolate-broccoli muffins.
Were = auxiliary verb; missing = present participle completing the verb phrase.
While Naomi was obsessing about her grade, Jason shared the data that she needed.
Was = auxiliary verb; obsessing = present participle completing the verb phrase.
Future progressive looks like this:
will + be + present participle
Use the future progressive tense to indicate an action that will continue in the future.
I will be growing broccoli in the backyard this spring.
Will, be = auxiliary verbs; growing = present participle completing the verb phrase.
Soon, Alex will be eating organic chocolate-broccoli muffins!
Will, be = auxiliary verbs; eating = present participle completing the verb phrase.
Form passive voice with be.
Active voice looks like this:
subject + verb + direct object.
Here are some samples:
We licked our lips.
Frank devoured a bacon double cheeseburger.
Everyone envied his enjoyment.
Passive voice makes these changes:
direct object as subject + form of be + past participle + by + subject as object of the preposition.
Now read these revisions:
Our lips were licked by us.
The double bacon cheeseburger was being devoured by Frank.
His enjoyment was envied by everyone.
Notice how wordy and clunky passive voice is! Now you know why English teachers tell you to avoid it!
Form perfect tenses with have.
All perfect tenses use a form of have. Present perfect follows this pattern:
has or have + past participle
Use the present perfect tense to convey an action or condition that began in the past but continues [or is finished] in the present.
Marge has bought earplugs to drown out her husband's snoring.
Has = auxiliary verb; bought = past participle completing the verb phrase.
The earplugs have saved Marge's marriage to George.
Have = auxiliary verb; saved = past participle completing the verb phrase.
Past perfect follows this pattern:
had + past participle
Use the past perfect tense to show that one action in the past occurred before another.
Because Marge had purchased the earplugs, she no longer fantasized about smothering George with a pillow.
Had = auxiliary verb; purchased = past participle completing the verb phrase.
Future perfect follows this pattern:
will + have + past participle
Use the future perfect tense to indicate that an action will be finished in the future.
This Sunday, Marge will have gotten an entire week of uninterrupted sleep.
Will, have = auxiliary verbs; gotten = past participle completing the verb phrase.
Form emphatic tenses with do.
When you use a form of do as an auxiliary verb, you form the emphatic tense. This tense is useful for asking questions or emphasizing an action. The patterns look like these:
form of do + main verb
form of do + subject + main verb ... ?
I did not eat your leftover pizza!
Did = auxiliary verb; eat = main verb completing the verb phrase.
Do you always accuse the first person you see?
Do = auxiliary verb; accuse = main verb completing the verb phrase.
Doesn't the evidence point to Samuel, who still has a bit of black olive stuck to his front tooth?
Does = auxiliary verb; point = main verb completing the verb phrase.
Understand the job of modal auxiliary verbs.
Modal auxiliary verbs never change form. You cannot add an ed, ing, or s ending to these words. Can, could, may, might, must, ought to, shall, should, will, and would have only one form.
You can use modal auxiliary verbs in these patterns:
modal + main verb
modal + be + present participle
modal + have + past participle
With modal auxiliaries, you can indicate necessity or obligation:
To lose her orange glow, Yvonne should eat fewer carrots.
John must remember his wife's birthday this year.
If Cecilia wants a nice lawn, she ought to be raking the leaves.
Or you can show possibility:
Fred might share his calculus homework if you offer him a slice of pizza.
Ann could have run the half marathon if she had started to train four months ago.
Modal auxiliaries also show willingness or ability:
Nicole will babysit your pet iguana for a reasonable fee.
Jason can pass chemistry this semester if he stops spending his study time at the arcade.