, an auxiliary
(also called helping verb
, helper verb
, auxiliary verb
, or verbal auxiliary
) is a verb
functioning to give further semantic
information about the main
or full verb
following it. In English
, the extra meaning an auxiliary verb imparts alters the basic form of the main verb to have one or more of the following functions: passive
, or dummy
In English, every clause has a finite verb which consists of a full verb (a non-auxiliary verb) and optionally one or more auxiliary verbs, each of which is a separate word. Examples of finite verbs include write (no auxiliary verb), have written (one auxiliary verb), and have been written (two auxiliary verbs).
There is a syntactic difference between an auxiliary verb and a full verb; that is, each has a different grammatical function within the sentence. In English, and in many other languages, there are some verbs that can act either as auxiliary or as full verbs, such as be ("I am writing a letter" vs "I am a postman") and have ("I have written a letter" vs "I have a letter"). In the case of be, it is sometimes ambiguous whether it is auxiliary or not; for example, "The ice cream was melted" could mean either "Someone/something melted the ice cream" (in which case melt would be the main verb) or "the ice cream was mostly liquid" (in which case be would be the main verb).
Functions of the English auxiliary verb
The auxiliary verb be
is used with a past participle
to form the passive voice
; for example, the clause "the door was opened
" implies that someone (or something) opened it, without stating who (or what) it was. Because many past participles are also stative adjectives, the passive voice can sometimes be ambiguous; for example, "at 8:25, the window was closed
" can be a passive-voice sentence meaning "at 8:25, someone closed the window," or a non-passive-voice sentence meaning "at 8:25, the window was not open". Perhaps due to this ambiguity, the verb get
will sometimes be used colloquially instead of be
in forming the passive voice, "at 8:25, the window got closed
The auxiliary verb be
is used with a present participle
to form the progressive aspect
; for example, the sentence "I am riding
my bicycle" describes what the speaker is doing at the very moment of utterance, while the sentence "I ride
my bicycle" is a temporally broader statement.
The auxiliary verb have
is used with a past participle
to form the perfect aspect
; for example, the sentence "Peter has fallen
in love" differs from "Peter fell in love" in that the former implies some connection to the present — likely that Peter is still in love — while the latter does not.
There are nine modal verbs: can, could, may, might, shall, should, will, would, and must. They differ from the other auxiliaries both in that they are defective verbs, and in that they can never function as main verbs. (There do exist main verbs can and will, but these are distinct.) They express the speaker's (or listener's) judgement or opinion at the moment of speaking. Some of the modal verbs have been seen as a conditional tense form in English.
Some schools of thought consider could to represent the past tense of can. However, according to Michael Lewis (The English Verb), this is not always true. "Could I get you something?" clearly is not expressing past time. Lewis instead suggests that could is a remote form of can. It is evident after re-examining the usage of could in this light that remoteness does describe the general meaning, e.g.
- I couldn't do it. (remoteness of time)
- It could happen. (remoteness of possibility)
- Could you do me a favor? (remoteness of relationship)
The remaining modal auxiliaries can be viewed in this same manner. Lewis covers this area in detail in his book; see the References section.
Because only auxiliaries can be inverted to form questions and only auxiliaries can take negation directly, a dummy auxiliary do
is used for questions and negatives when only a full verb exists in the positive statement (i.e. there are no auxiliaries in the positive, non-interrogative form). The same dummy do
is used for emphasis in the positive statement form. This is known as do
For example, if the positive statement form is:
the interrogative, negative and emphatic forms are respectively:
- Do I know the way?
- I don't know the way.
- I do know the way.
Compare this with:
- Should I know the way?
- I shouldn't know the way.
- I should know the way.
The emphatic form would normally be marked by intonation or punctuation of 'I' or 'should'. With the first two forms it depends on context.
English contains many verb phrases that function as quasi-auxiliaries, such as be going to, used to, is about to. These quasi-auxiliaries require an infinitive. Others take a gerund (e.g. need, as in need fixing, in American English), past participle (e.g. get, as in get done), or other verb form.
In American English, go and come can be quasi-auxiliaries with nothing between them and the following verb phrases, but only in their plain forms: "Come show me", "I'll go get it", and "I had to come see for myself". This use can be regarded as ellipsis of and — the previous are equivalent to "Come and show me", "I'll go and get it", and "I had to come and see for myself" — and British English requires the and to be included, as does American English when the verb is not in its plain form: "I went and saw him." (It is also possible in both dialects for to to be used in place of and, though this typically has a slightly different sense.)
Properties of the English auxiliary verb
Auxiliaries take not
(or n't) to form the negative, e.g. can't, won't, shouldn't, etc. In certain tenses, in questions, when a contracted auxiliary verb can be used, the position of the negative
moves from the main verb to the auxiliary: cf. Does it not work?
and Doesn't it work?
. This has not always been the case as the following sentence from Jane Austen's 'Pride & Prejudice' indicates: 'The country is a vast deal pleasanter, is it not, Mr. Bingley?'.
Auxiliaries invert to form questions:
- You will come.
- Will you come?
The dummy auxiliary do
is used for emphasis in positive statements (see above):
Auxiliaries can appear alone where a main verb has been omitted, but is understood:
- I will go, but she won't [go].
The verb do can act as a pro-VP (or occasionally a pro-verb) to avoid repetition:
- John never sings in the kitchen, but Mary does. (pro-VP: replaces sings in the kitchen)
- John never sings in the kitchen, but Mary does in the shower. (pro-verb: replaces sings)
Auxiliaries can be repeated at the end of a sentence, with negation added or removed, to form a tag question. In the event that the sentence did not use an auxiliary verb, a dummy auxiliary (a form of do
) is used instead:
- You will come, won't you?
- You ate, didn't you?
- You won't come, will you?
- You didn't eat, did you?
In Scottish English
An example was made famous by Hamish and Dougal
- You'll have had your tea?
as a greeting. The implication is that I (having made the utterance) am not going to put myself in the position in which I would have to offer you tea, lest you had not had any.
More common, is the construction of the form
- You'll not be wanting a drink?
uttered by a person who should offer you one but wishes not to.
In Indo-European languages
, the verb "to have" is the most common auxiliary used for perfect tenses
has inherited this use of the verb. Some languages use "to be" for the perfect forms of some or all verbs (in Esperanto
, for example, Mi estis irinta
(I was having-gone = I had gone). French
, and Dutch
use it for verbs of motion and becoming
, and (in German and Dutch) for "to be" itself, as does Italian
. The use of auxiliaries is one variation among Romance languages
. English uses "to be" only with "to go" in some senses.
Finnish, a Uralic language, uses olla (to be) for all verbs: Sillä niin on Jumala maailmaa rakastanut (Because so is God the world loved); it lacks an equivalent of the verb to have. Finnish also has a negative auxiliary verb ei, which conjugates like all Finnish verbs; thus:
- "I understand" is Ymmärrän
- and "I don't understand" is En ymmärrä
- where the action verb is non-finite
Similar negative auxiliary verbs are found in Nivkh and the Salish and Chimakuan languages formerly spoken in northwestern North America. Salish and Chimakuan languages also have interrogative auxiliary verbs that form questions in the same manner as negative verbs do negated statements.
In many non-Indo-European languages, the functions of auxiliary verbs are largely or entirely replaced by suffixes on the main verb. this is especially true of epistemic possibility and necessity verbs, but extends to situational possibility and necessity verbs in many indigenous languages of North America, indigenous Australian languages and Papuan languages of New Guinea.
- The English Verb 'An Exploration of Structure and Meaning', Michael Lewis. Language Teaching Publications. ISBN 0-906717-40-X