haveauxiliary

Haveauxiliary is a linguistic term sometimes used to describe the use of the English verb have as an auxiliary to form perfect tenses and related constructions. In standard grammar, have functions as an auxiliary rather than as a main verb, unlike the main verb have, which denotes possession. The concept is common in descriptions of English syntax, though the exact label “haveauxiliary” is not universally used in all grammars.

In present perfect constructions, have serves as the auxiliary and is conjugated to agree with the subject: I have eaten, you have finished, he has arrived. In third person singular, have becomes has. In the past perfect, the form is had eaten for all subjects. In the future perfect, will have eaten expresses an action that will be completed by a future point: They will have finished by tomorrow.

Have is also used in negative and interrogative forms: I have not seen that; Have you finished? Contractions are common (haven’t, hasn’t, hasn’t). The auxiliary can participate in more complex shapes, such as the present perfect progressive (I have been waiting) and the perfect passive (The work has been completed). The sequence have + been + past participle enables perfect passive constructions as well as continuous aspects when combined with the participle form.

Distinctions from be as an auxiliary are important: be forms the progressive aspect and the passive voice, while have primarily marks perfect aspect. The two auxiliaries can combine in structures like have been + past participle for the present perfect passive (The song has been sung).

Historically, the development of have as an auxiliary part of the periphrastic perfect is a feature of English and is shared with related Germanic languages, though the exact terminology varies. See also: perfect aspect, auxiliary verb, present perfect, past perfect, future perfect.