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Concourse 2

Primary Auxiliary verbs




An auxiliary verb is one which cannot usually stand alone and retain a clear meaning.  Compare, for example,

  1. He can
  2. He went
  3. They are
  4. She smokes

It's clear that the meanings of sentences 1. and 3. are obscure unless we have some more information.  We need to know what He can do and What they are or are doing.
Sentences 2. and 4., however, are complete in themselves and need no further elaboration.
The verbs can and are in these examples are auxiliary verbs and the verbs went and smokes are main or lexical verbs.  This is a crucial distinction.

In addition to issues of meaning seen above, there are grammatical characteristics of auxiliary verbs which can be used to identify them.  A list of 10 tests to identify central modal auxiliary verbs (such as can, could, may, might, should etc.) is set out in the guide to them, linked below.  Primary auxiliary verbs are, by contrast, rather easier to identify because they perform three essential functions in the language:

  1. They form tenses of verbs as in, for example:
        Mary has arrived
        She is running the business
        The money will run out soon
  2. They change the voice of a clause, from active to passive or from active to causative, as in, for example:
        The garden was tidied (vs. Someone tidied the garden)
        The car got damaged by a falling tree (vs. A falling tree damaged the car)
        She had her hair cut (vs. Someone cut her hair)
        She got her money stolen (vs. Someone stole her money)
  3. They form questions, negatives and emphatic statements as in, e.g.:
        Do you want to come with us?
        She didn't see the reasoning
        I do like her

    Only the auxiliary verb do performs this function.

This guide considers five primary auxiliary verbs: be, have, get, do and will.

Before we start, however, we need to consider three complicating factors.


Complication 1

There are two kinds of auxiliary verbs in English: Primary Auxiliaries and Modal Auxiliaries.
Modal Auxiliary verbs include, for example, can, may, might, should, ought to etc.  These verbs express notions such as possibility, permission, obligation, likelihood and so on.  There are guides to these elsewhere on the site.  The place to start is the guide to modality, linked in the list of related guides at the end.
The ones in focus here are the primary auxiliaries.


Complication 2

Some primary auxiliary verbs can function in both ways.  They can be auxiliaries and they can also be lexical or main verbs.  For example, in these sentences the verbs get, do, will, be and have are functioning in both ways.  Can you identify which is which?
Click here when you have an answer.

  1. They got home late
  2. We got the work done
  3. He did the crossword puzzle in three minutes
  4. Did she arrive?
  5. Mary willed the rain to stop
  6. Mary will be 21 on Thursday
  7. She is a teacher
  8. She is arriving now
  9. She has the papers
  10. She has been to the USA

Here, we are only concerned with verbs acting as auxiliaries.


Complication 3

Some auxiliaries (notable will) are usually called modal but often act to give grammatical information by forming a tense with a main verb.  For this reason, some people will classify will and would as Primary Auxiliary verbs.  That is a sensible approach because both verbs can act in both ways.  The classification is then split so when they act as primary modal auxiliaries, that is what they should be called and, likewise, when they act as modal auxiliary verbs.
We are going to include the verb will , its alternative shall and its past form would in this guide because it sometimes acts as a primary auxiliary verb.  That it also acts as a modal auxiliary verb is a source of a good deal of confusion for learners and, alas, many teachers and even some coursebook writers.
If you want to learn more about the functions of will and would, go to the guide to modality.  See also below.


What do the Primary Auxiliary verbs actually do?

Auxiliary verbs in general are sometimes called 'helping verbs' and, although that is rather babyish, there is a kernel of truth in it.  Primary Auxiliaries help in the sense that they provide grammatical information and tell us how to view the lexical or main verb which follows.
We'll take them one by one.


The first thing to note about this verb is that it is very frequently seen as a lexical or main verb in things such as:
    He did the work carefully
    She is doing her homework
    They do that a lot
etc. and in these cases, the verb carries the meaning of perform an action.  As a lexical verb, do can carry other meanings but the lexical verb does not concern us here.

The second thing to note is that this verb only functions as a Primary Auxiliary verb in present simple and past simple tenses.  Nowhere else.  For this reason, it is often referred to as an operator because it can operate on a main verb in, for example:
    He does enjoy music
in which the verb takes on the ending (es) which would normally occur on the lexical or main verb (enjoys).
In this case, it simply serves to emphasise the verb enjoy.  That is only one of its functions.

do as a Primary Auxiliary verb

What function is the verb do performing in these examples?

  1. Did you see the film?
  2. I don't understand
  3. I do demand it
  4. Don't talk to me

Click here when you have an answer.

The summary of do:


In questions, imperatives and negatives, the verb is not usually stressed.  The stress in these cases is on the lexical or main verb because that is carrying the meaning.  In emphasising uses, however, the verb is stressed.


Again, have can function as a lexical or main verb and frequently does.  For example:
    I have a shower every evening (meaning, roughly, take)
    I have his address (meaning, roughly, possess)

When it is a lexical or main verb, we can:

The third thing to note is that when the verb is a Primary Auxiliary, we never use the do auxiliary with it.  Never.  It is not possible to say something like
    *Do you have met him?
and that is a cause for error at lower levels especially.

The fourth complication is that have when it is followed by to + an infinitive is a modal auxiliary verb akin to must as in, e.g.
    I have to leave now
and in this case it does not qualify as a primary auxiliary verb but is a modal auxiliary verb.

have as a Primary Auxiliary verb

What function is the verb have performing in these examples?

  1. Have you seen the film?
  2. I won't have done it by the time the boss gets here
  3. I haven't eaten this before
  4. He has spent all his money
  5. He had already left when I arrived
  6. I hadn't expected something so beautiful, had you?
  7. I had my tooth taken out
  8. I'll have the window repaired

Click here when you have an answer.

The summary of have:



The verb be can function as a lexical or main verb and usually expresses:

  1. The relationship between two things in, for example
        She is a teacher
        It is a mistake
  2. The characteristics of something in, e.g.,
        They are French
        He is very clever

In these cases it is known as a copular verb and joins two things together.  For more, see the guide to copular verbs.

The second thing to notice is that this verb has eight different forms (most have only four or five):

  1. be
  2. am
  3. is
  4. are
  5. was
  6. were
  7. being
  8. been

All of these can be used when the verb is acting as a lexical or main verb or as an auxiliary.  That is confusing for learners at lower levels.  Here is this very irregular verb compared to a regular lexical or main verb, smoke, so you can see the complications: 

To show: be smoke
Infinitive be smoke
First person singular (I) am
Second person singular or plural (you) are
Third person plural (they)
First person plural (we)
Third person singular (he, she, it) is smokes
Present participle / gerund being smoking
Past participle been smoked
First person singular (past) was
Second person singular (past)
First person plural (past) were
Third person plural (past)

be as a Primary auxiliary verb

What function is the verb be performing in these examples?

  1. I am seeing him tomorrow?
  2. They were playing tennis at the time
  3. She was explaining it to me
  4. He was banging on the door
  5. The window was broken by a bird
  6. The car has been repaired

Click here when you have an answer..

The summary of be:



This guide is slightly unusual in classifying get as a Primary Auxiliary verb but it can function this way as well as functioning as a lexical or main verb.
As a lexical verb it has a very wide range of meanings.  Some dictionaries will list over 40 different meanings of the verb ranging from achieve, reach, arrive etc. to become, grow and leave.  Adding particles to get such as on, out, over, to etc. adds even more meanings.
Here, however, we are interested in get as a primary auxiliary verb.

get as a Primary Auxiliary verb

What function is the verb be performing in these examples?

  1. I got the house painted
  2. She got her foot trapped
  3. The window got damaged
  4. They will get arrested for it

Click here when you have an answer.

So, in sentences a. and b., we can replace get with have and in sentences c. and d., we can replace it with be.
In both cases get is usually less formal.

The summary of get:



We noted at the beginning that not all analyses consider this verb to be a primary auxiliary verb.  We do in this guide, however, because in one of its functions, it acts as a primary auxiliary verb.

The verb has a number of meanings considered at length elsewhere on this site (see the guide to will and would linked below, for example).
The three main meanings it carries are:

  1. As a lexical verb.
    When will is used in this way it is a regular verb with two meanings:
    1. bequeath as in pass down to the next generation as in, e.g.:
          He willed his entire fortune to his dog
    2. exercise mental power (usually pointlessly) as in, e.g.:
          He willed the rain to stop
    These meanings of the verb do not concern us here.
  2. As a modal auxiliary verb indicating willingness or volition.  For example:
        I'll take you to the station if you like
        Mary says she'll help with the work

    In this meaning, the past tense is formed as would so we can also get:
        I promised I would take you to the station
        Mary said she would help

        John would always help his children with their homework
    The verb when it acts in this way indicates what is known as dynamic or personal modality because it concerns the speaker's willingness to do something.
    The last example above, concerning homework is often analysed as the verb signalling habitual activity in the past and it does do that.  Here, however, it also implies a past willingness to do something and is acting as a modal auxiliary verb expressing dynamic modality.
    It can also act to express how likely something is in the speaker's view so we also get, for example:
        That will be the postman the dog is barking at
        I expect John will be working now

    with both signifying that the speaker is fairly (not 100%) sure of the truth of what is said.
    Neither of these uses of the verb concern us here because they are modal meanings concerning the speaker's willingness or belief.
  3. As a primary auxiliary verb forming part of a future tense form.
    This is the use that does concern us here because the main function of primary auxiliary verbs is grammatical and in this case the way that English forms a tense referring to pure futurity is to use will or shall as a primary auxiliary verb.  For example:
        I will be 35 tomorrow
        I shall not be in London before 6
        They'll expect an answer

        It will be cold in Alaska at this time of year
        Mary will be chairing the meeting
    and so on all refer to the future and make no statement at all about the willingness of the people.  In the example about Alaska, of course, willingness or otherwise is not even in consideration because the weather cannot show volition.
    In the last example, we have a slightly different future tense form which implies that something will happen as a matter of course.


The serious complication here is that it is often not clear whether someone is using the verb as a modal auxiliary or a primary auxiliary verb.  See if you can identify the function of the verb in these cases and then click on the eye open for some comments:

Will you marry me?
eye open
Do you think she will marry him?
eye open
I will talk to you tomorrow
eye open
Jane thought she would be early
eye open
Shall we go?
eye open
I shan't be able to come
eye open
You will not speak to my mother like that
eye open
I won't be necessary to get a visa
eye open
I wouldn't do that, even if you paid me
eye open
She will be at the meeting if her train is on time
eye open

You can see from that little exercise that it is not easy to disentangle the meanings in all cases.  However, if we do not try with learners to make sure that the meanings of will / shall / would acting as a modal auxiliary verb or acting as a primary auxiliary verb are clear, we are asking for trouble.
Many languages, including Romance languages such as Italian, French, Spanish and more and most Slavic languages, have a special tense form for the future which English does not have.
Other languages (such as Dutch and German, Danish, Swedish and Norwegian) work a little like English in using an auxiliary verb but these languages do not all have the added complication of using the same verb to signal both willingness and futurity.
Some languages, including Chinese languages, some south-east Asian languages and Greek use a particle to denote a future time reference rather as English uses will.

The summary of will:



The anomalous nature of used

If we are including the verb would in its sense of signalling a discontinued habit, as in, e.g.:
    We would often take a trip to the market
as forming a past tense with a habitual aspect, then it is a logical extension to classify. e.g.:
    We often used to take a trip to the market
as equally an example of the verb used, followed in this case with the to-infinitive as performing a primary rather than modal function.
That is to say, that the verb forms a tense rather than expressing the usual modal meanings of obligation, likelihood, doubt, certainty and so on.
However, most authorities persist in classifying the structure used + to-infinitive as a semi-modal verb and that is what is done in the guide to those verbs on this site (link below).


Here's the big picture:


Take a short test on some of this.

Related guides
modality essentials for a guide to the other sort of auxiliary verbs
PDF document for a list of primary and modal auxiliary verbs
modal auxiliary verbs for a traditional guide to pure (or central) modal auxiliary verbs
semi-modal auxiliary verbs the more technical guide to semi- and marginal modal auxiliary verbs
will and would for more about the difficulties of this verb
tense and aspect to see how primary auxiliaries work to make tense and aspect forms and how will operates
voice with a focus on the active and passive
copular verbs for a guide to how be and other verbs work to link the subject and complement
the present perfect for a guide to how have works to form the language's most troublesome and misunderstood tense
the passive voice for the in-service guide to a tricky area
the causative a more technical guide to using have and get to make a form of the passive