Editing Auxiliary verb (section)

==English==
{{main article|English auxiliaries and contractions}}
The following sections consider auxiliary verbs in English. They list auxiliary verbs, then present the diagnostics that motivate this special class (subject-auxiliary inversion and negation with ''not''). The [[modal verb]]s are included in this class, due to their behavior with respect to these diagnostics.

===List of auxiliaries in English===
A list of verbs that (can) function as auxiliaries in English is as follows:<ref>For lists of the auxiliary verbs like the one produced here but with minor discrepancies, see for instance Radford (2004:324), Crystal (1997:35), and Jurafsky and Martin (2000:322).</ref>

::''be'', ''can'', ''could'', ''dare'', ''do'', ''have'', ''may'', ''might'', ''must'', ''need'', ''ought'', ''shall'', ''should'', ''will'', ''would''

The status of ''dare (not)'', ''need (not)'', and ''ought (to)'' is debatable<ref>For some discussion of the status of ''dare'' as a "marginal modal", see Fowler's Modern English Usage, p. 195f.</ref> and the use of these verbs as auxiliaries can vary across dialects of English. If the negative forms ''can't'', ''don't'', ''won't'', etc. are viewed as separate verbs (and not as contractions), then the number of auxiliaries increases. The verbs ''do'' and ''have'' can also function as full verbs or as [[light verb]]s, which can be a source of confusion about their status. The [[English modal verb|modal verb]]s (''can'', ''could'', ''may'', ''might'', ''must'', ''shall'', ''should'', ''will'', ''would'', and ''dare'', ''need'' and ''ought'' when included) form a subclass of auxiliary verbs. Modal verbs are [[Defective verb|defective]] insofar as they cannot be [[inflection|inflected]], nor do they appear as gerunds, infinitives, or participles.

The following table summarizes the auxiliary verbs in standard English and the meaning contribution to the clauses in which they appear. Many auxiliary verbs are listed more than once in the table based upon discernible differences in use.

{| class="wikitable"
|-
! Auxiliary verb !! Meaning contribution !! Example
|-
| be<sub>1</sub> || [[Copula (linguistics)|copula]] (= [[linking verb]]) || She '''is''' the boss. 
|-
| be<sub>2</sub> || [[progressive aspect]] || He '''is''' sleeping.
|-
| be<sub>3</sub> || [[passive voice]] || They '''were''' seen.
|-
| can<sub>1</sub> || [[deontic modality]] || I '''can''' swim. 
|-
| can<sub>2</sub> || [[epistemic modality]] || Such things '''can''' help.
|-
| could<sub>1</sub> || deontic modality || I '''could''' swim.
|-
| could<sub>2</sub> || epistemic modality || That '''could''' help. 
|-
| dare || deontic modality || I '''dare''' not attempt it.
|-
| do<sub>1</sub> || [[do-support]]/emphasis || You '''did''' not understand.
|-
|do<sub>2</sub>
|question
|'''Do''' you like it?
|-
| have || [[perfect aspect]] || They '''have''' understood.
|-
| may<sub>1</sub> || deontic modality || '''May''' I stay?
|-
| may<sub>2</sub> || epistemic modality || That '''may''' take place.
|-
| might || epistemic modality || We '''might''' give it a try.
|-
| must<sub>1</sub> || deontic modality || You '''must''' not mock me.
|-
| must<sub>2</sub> || epistemic modality || It '''must''' have rained.
|-
| need || deontic modality || You '''need''' not water the grass.
|-
| ought || deontic modality || You '''ought''' to play well.
|-
| shall || deontic modality || You '''shall''' not pass.
|-
| should<sub>1</sub> || deontic modality || You '''should''' listen.
|-
| should<sub>2</sub> || epistemic modality || That '''should''' help. 
|-
| will<sub>1</sub> || epistemic modality || We '''will''' eat pie.
|-
| will<sub>2</sub> || [[future tense]] || The sun '''will''' rise tomorrow at 6:03.
|-
| will<sub>3</sub> || [[habitual aspect]] || He '''will''' make that mistake every time.
|- 
| would<sub>1</sub> || epistemic modality || Nothing '''would''' accomplish that.
|-
| would<sub>2</sub> || [[future-in-the-past]] tense || After 1990, we '''would''' do that again.
|-
| would<sub>3</sub> || habitual aspect || Back then we '''would''' always go there.
|}

Deontic [[Modality (grammar)|modality]] expresses an ability, necessity, or obligation that is associated with an agent subject. Epistemic modality expresses the speaker's assessment of reality or likelihood of reality. Distinguishing between the two types of modality can be difficult, since many sentences contain a modal verb that allows both interpretations.

=== List of auxiliaries unique to African American Vernacular English ===
[[African-American Vernacular English|African American Vernacular English]] makes a variety of finer [[Tense–aspect–mood|tense/aspect]] distinctions than other dialects of English by making use of unique variant forms of, in particular: [[Habitual be|habitual 'be']], reduced 'done' (dən), and stressed 'been' (BIN):<ref>{{Cite book|last=Green, Lisa J., 1963–|title=African American English : a linguistic introduction|date=2002|publisher=Cambridge University Press|isbn=0-511-07823-4|location=Cambridge, U.K.|oclc=57572547}}</ref><ref>Green, Lisa J. & Walter Sistrunk. 2015. Syntax and Semantics in African American English. In Jennifer Bloomquist, [[Lisa Green (linguist)|Lisa J. Green]] & [[Sonja Lanehart|Sonja L. Lanehart]] (eds.), ''The Oxford Handbook of African American Language''. Oxford University Press. {{doi|10.1093/oxfordhb/9780199795390.013.15}} http://www.oxfordhandbooks.com/view/10.1093/oxfordhb/9780199795390.001.0001/oxfordhb-9780199795390-e-15 (10 June 2020).</ref>
{| class="wikitable"
|+Verbal Auxiliaries in AAVE
!Auxiliary
!Meaning
!Example
|-
|be
|[[Habitual aspect|habitual]] aspect
|She '''be''' telling people she eight.
'She is always telling people she's eight'
|-
|done
|[[resultative]] modality
|I '''done''' pushed it.

'I have (already) pushed it'
|-
|been
|[[Past tense|distant past]] tense
|I '''been''' knew that.

'I've known that for a long time'
|}

===Diagnostics for identifying auxiliary verbs in English===
The verbs listed in the previous section can be classified as auxiliaries based upon two diagnostics: they allow [[subject–auxiliary inversion]] (the type of inversion used to form questions etc.) and (equivalently) they can take ''not'' as a postdependent (a dependent that follows its [[head (linguistics)|head]]). The following examples illustrate the extent to which subject–auxiliary inversion can occur with an auxiliary verb but not with a full verb.<ref>For examples of the inversion diagnostic used to identify auxiliaries, see for instance Radford (1997:50f., 494), Sag and Wasow (1999:308f.), and Kroeger (2004:253).</ref> (The asterisk * is the means commonly used in linguistics to indicate that the example is grammatically unacceptable or that a particular construction has never been attested in use).

::a. '''He was''' working today.
::b. '''Was he''' working today? <small>- Auxiliary verb ''was'' allows subject–auxiliary inversion.</small>

::a. '''He worked''' today.
::b. *'''Worked he''' today? <small>- Full verb ''worked'' does not allow subject–auxiliary inversion.</small>

::a. '''She can''' see it.
::b. '''Can she''' see it? <small>- Auxiliary verb ''can'' allows subject–auxiliary inversion.</small>

::a. '''She sees''' it.
::b. *'''Sees she''' it? <small>- Full verb ''sees'' does not allow subject–auxiliary inversion.</small>

The following examples illustrate that the negation ''not'' can appear as a postdependent of a finite auxiliary verb, but not as a postdependent of a finite full verb:<ref>The negation diagnostic for identifying auxiliary verbs is employed for instance by Radford (1997:51), Adgar (2003:176f.), and Culicover (2009:177f.).</ref>

::a. Sam would try that.
::b. Sam would '''not''' try that. <small>- The negation ''not'' appears as a postdependent of the finite auxiliary ''would''.</small>

::a. Sam tried that.
::b. *Sam tried '''not''' that. <small>- The negation ''not'' cannot appear as a postdependent of the finite full verb ''tried''.</small>
::a. Tom could help.
::b. Tom could '''not''' help. <small>- The negation ''not'' appears as a postdependent of the finite auxiliary ''could''.</small>

::a. Tom helped.
::b. *Tom helped '''not'''. <small>- The negation ''not'' cannot appear as a postdependent of the finite full verb ''helped''.</small>

A third diagnostic that can be used for identifying auxiliary verbs is verb phrase ellipsis. See the article on [[verb phrase ellipsis]] for examples.

These criteria lead to the [[copula (linguistics)|copula]] ''be'' and non-copular use of ''be'' as an [[Existential clause|existential]] verb being considered an auxiliary (it undergoes inversion and takes postdependent ''not'', e.g., ''Is she the boss?'', ''She is not the boss'', ''Is there a God?'', ''There is a God''). However, if one defines ''auxiliary verb'' as a verb that somehow "helps" another verb, then the copula ''be'' is not an auxiliary, because it appears without another verb. The literature on auxiliary verbs is somewhat inconsistent in this area.<ref>Jurafsky and Martin (2000:320) state clearly that copula ''be'' is an auxiliary verb. Bresnan (2001:18f) produces and discusses examples of subject-auxiliary inversion using the copula. Tesnière (1959) repeatedly refers to the copula ''être'' in French as an auxiliary verb, and Eroms (2000:138f.) discusses the copula ''sein'' in German as a ''Hilfsverb'' 'helping verb'. Crystal (1997:35) lists ''be'' as an auxiliary verb without distinguishing between its various uses (e.g., as a copula or not). Other definitions are less clear; Radford (2004:324) suggests that copula ''be'' is not an auxiliary, but he does not address why it behaves like an auxiliary with respect to the criteria he employs (e.g., inversion) for identifying auxiliaries.</ref>

There are also some properties that some but not all auxiliary verbs have. Their presence can be used to conclude that the verb is an auxiliary, but their absence does not guarantee the converse. One such property is to have the same form in the present tense, also for the first and the third person singular. This in particular is typical for ''[[modal verb|modal]]'' auxiliary verbs, such as ''will'' and ''must''. (Examples: ''He will come tomorrow'', ''she must do it at once'', not <s>''he wills''</s> or <s>''she musts''</s>.)