In English grammar, a helping verb is a verb that comes before the main verb (or lexical verb) in a sentence. Together the helping verb and the main verb form a verb phrase. (A helping verb is also known as an auxiliary verb.)

A helping verb always stands in front of a main verb. For example, in the sentence Shyla can ride her sister's bicycle, the helping verb can stand in front of ride, which is the main verb.

More than one helping verb can be used in a sentence. For example, in the sentence Shyla could havewalked to school, there are two helping verbs: could and have.

Sometimes a word (such as not) separates the helping verb from the main verb. For example, in the sentence Shyla does not want a new bicycle, the negative particlenot comes between the helping verb does, and the main verb want.

Helping Verbs in English

• is, am, are, was, were
• be, being, been
• has, have, had
• do, does, did
• will, shall, should, would
• can, could
• may, might, must

Examples and Observations

'[Some] helping verbs (forms of have, be, and do) may also function as main verbs. In addition, nine modal verbs (can, could, may, might, must, shall, should, will, would) function only as helping verbs. Have, be, and do change form to indicate tense; the nine modals do not.'

(Walter E. Oliu, Charles T. Brusaw, and Gerald J. Alred, Writing That Works: Communicating Effectively on the Job, 10th ed. Bedford/St. Martin's, 2010)

• 'I have always hated those upstart space toys.'(Stinky Pete the Prospector in Toy Story 2, 1999)
• 'If we love our country, we should also love our countrymen.'(Ronald Reagan)
• 'We can stay up late, swapping manly stories.'(Donkey in Shrek, 2001)
• 'Nothing great was ever achieved without enthusiasm.'(Ralph Waldo Emerson)
• 'Life has taught us that love does not consist in gazing at each other, but in looking outward together in the same direction.'(Antoine de Saint-Exupery)
• 'A pigeon landed nearby. It hopped on its little red feet and pecked into something that might have been a dirty piece of stale bread or dried mud.'(Isaac Bashevis Singer, 'The Key.' The New Yorker, 1970)

Functions of Helping Verbs

'Helping verbs indicate shades of meaning that cannot be expressed by a main verb alone. Consider the differences in meaning in the following sentences, in which the helping verbs have been italicized:

I may marry you soon.
I must marry you soon.
I should marry you soon.
I can marry you soon.

As you can see, changing the helping verb changes the meaning of the entire sentence. These differences in meaning could not be expressed simply by using the main verb, marry, alone.'

(Penelope Choy and Dorothy Goldbart Clark, Basic Grammar and Usage, 7th ed. Thomson, 2008)

More Functions of Helping Verbs

'Helping verbs . . . enable us to express various conditions: If he could type, he would write the next great American novel. Helping verbs help us express permission: You may go to the movie. Helping verbs help us express one's ability to do something: She can play golf extremely well. Helping verbs enable us to ask questions: Do you think he cares? Will he win the race?'

(C. Edward Good, A Grammar Book for You and I-- Oops, Me! Capital Books, 2002)

How to Use Helping Verbs to Change Active Voice to Passive Voice

'If the active sentence is in the past tense, then the full verb in the passive version will be as well: Monica groomed the poodle → The poodle was groomed by Monica.

1. Monica moves to the end of the sentence; add by, so prepositional phrase is by Monica.
2. The poodle moves to the front into the subject slot.
3. Helping verb be is added in front of the main verb.
4. Past tense marker jumps off groomed and onto helping verb be.
5. Helping verb agrees with new subject (third personsingular) = was.
6. Main verb groomed converts to its past participle form = groomed.'

(Susan J. Behrens, Grammar: A Pocket Guide. Routledge, 2010)