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verbs: helping verbs, auxiliary verbs

A helping (or auxiliary) verb is placed in front of a main verb to form a verb phrase (a verb of two or more words: are going, will be competing, etc.).

There are two types of helping verbs: primary helping verbs and modal helping verbs.

Primary helping verbs

The three primary helping verbs are be, do and have. Note that these helping verbs may take different forms, as shown below:

  • be, am, is, are, was, were, been, being
  • do, does, did
  • have, has, had

When be and have are used as helping verbs, the main verb that comes after them almost always changes its form:

  • are making [making is the present participle form of make]
  • were kept [kept is the past participle form of keep]
  • has decided [decided is the past participle form of decide]
  • have left [left is the past participle form of leave]

In addition to acting as helping verbs, be, do and have can act as main verbs:

  • I was at the arcade. [was is a main verb]
  • I was working at the arcade. [was is a helping verb; working is the main verb]
  • Lars often did the cooking. [did is a main verb]
    Lars did not mind cooking. [did is a helping verb; mind is the main verb]
  • Adam and Cara have the keys. [have is a main verb]
    Adam and Cara have left. [have is a helping verb; left is the main verb]

Modal helping verbs

There are 9 principal modal verbs:

  • can, could
  • shall, should
  • will, would
  • may, might
  • must

After these modal verbs, the main verb does not change its form; it is always in its base form (the form in which it is listed in the dictionary):

  • can go
  • will go
  • might go
  • should go

Modals are invariable.

Unlike the primary helping verbs, modal verbs do not change their form to agree with different subjects. In the examples below, can does not change, no matter what subject it follows:

  • I can go
  • you can go
  • he can go
  • we can go
  • they can go

Modals are not used alone.

Unlike the primary helping verbs, the modal verbs must always be used with a main verb. They occur alone only when the main verb has already been used once and is being left understood the second time to avoid repetition:

  • "Who can tell me the answer?" "Ican!" [= I can tell you the answer]
  • Lisa may not go, but Jorge will. [= Jorge will go]

Modals come before primary helping verbs.

In a verb phrase containing both modal and primary helping verbs, the modal verb comes first:

  • might be going
  • may have intended
  • can be found
  • will have been completed

Uses of helping verbs

We use helping verbs for the following purposes:

  • to change the tense of a verb:
    • am hoping [present progressive]
    • have finished [present perfect]
    • will go [simple future]
    • will have been taking [future perfect progressive]
  • to form the passive voice (with a form of be as the last or only helping verb):
    • were introduced
    • have been elected
    • is being organized
    • will be held
    • would have been hired
  • to form a negative verb:
    • The children did not (or didn’t) see the end of the hockey game.
    • Anna does not (or doesn’t) work here anymore.
    • Please do not (or don’t) open this window.

Note: Adverbs (such as the adverb not or its contraction n’t) often appear in the middle of a verb phrase—but they are not verbs. They modify the verb phrase but are not part of it.

  • to ask a question:
    • Do I have the wrong number?
    • Does Sven know Marta’s password?
    • Did you forget to walk the dog?
  • to create emphasis:
    • Rivka does plan to attend, after all.
    • We do need a new couch, no matter what you think!
    • I did walk the dog. Don’t you remember?
  • to add an idea:
    • necessity: must read
    • ability: can read
    • permission: may read
    • possibility: might read
    • advisability: should read