Editing Auxiliary verb (section)

==Traits across languages==
Auxiliary verbs typically help express grammatical [[tense (grammar)|tense]], [[grammatical aspect|aspect]], [[grammatical mood|mood]], and [[grammatical voice|voice]]. They generally appear together with an infinitive. The auxiliary is said to "help" the infinitive. The auxiliary verbs of a language form a [[closed class]], i.e., there is a fixed, relatively small number of them.<ref>Concerning auxiliaries forming a closed class, see Kroeger (2004:251).</ref>

Widely acknowledged verbs that can serve as auxiliaries in English and many related{{clarify|date=October 2012}} languages are the equivalents of ''be'' to express passive voice, and ''have'' (and sometimes ''be'') to express [[perfect aspect]] or past time reference.<ref>That the equivalents of ''have'' and ''be'' are perhaps the most widely acknowledged auxiliaries across languages (related to English) can be verified by glancing at the literature on auxiliaries, e.g., Engel (1994:104ff.), Eroms (2000:137ff.), Rowlett (2007:24ff.).</ref>

In some treatments, the [[Copula (linguistics)|copula]] ''be'' is classed as an auxiliary even though it does not "help" another verb, e.g.,

::The bird '''is''' in the tree. <small>– ''is'' serves as a copula with a [[predicative expression]] not containing any other verb.</small>

Definitions of auxiliary verbs are not always consistent across languages, or even among authors discussing the same language. [[Modal verb]]s may or may not be classified as auxiliaries, depending on the language. In the case of English, verbs are often identified as auxiliaries based on their grammatical behavior, as described below. In some cases, verbs that function similarly to auxiliaries, but are not considered full members of that class (perhaps because they carry some independent lexical information), are called ''semi-auxiliaries''. In French, for example, verbs such as ''devoir'' (have to), ''pouvoir'' (be able to), ''aller'' (be [[going to]]), ''vouloir'' (want), ''faire'' (make), and ''laisser'' (let), when used together with the infinitive of another verb, can be called semi-auxiliaries.<ref>Concerning the term ''semi-auxiliaries'' for French, see Warnant (1982:279).</ref> There has also been a study on auxiliary verb constructions in Dravidian languages.<ref>Anderson, Gregory D. S. 2015. “Areal-typological perspectives on the morphosyntax of auxiliary verb constructions in Dravidian languages.” In G. K. Panikkar, B. Ramakrishna Reddy, K. Rangan and B. B. Rajapurohit (eds.) V. I. Subramoniam Commemoration Volume I. Studies on Dravidian. Thiruvananthapuram: International School of Dravidian Linguistics, pp. 61–79.</ref>{{Relevance inline|reason=What is the significance or result of this statement?|date=May 2022}}