Auxiliary verb

An auxiliary verb (abbreviated aux) is a verb that adds functional or grammatical meaning to the clause in which it occurs, so as to express tense, aspect, modality, voice, emphasis, etc. Auxiliary verbs usually accompany an infinitive verb or a participle, which respectively provide the main semantic content of the clause. An example is the verb have in the sentence I have finished my lunch. Here, the auxiliary have helps to express the perfect aspect along with the participle, finished. Some sentences contain a chain of two or more auxiliary verbs. Auxiliary verbs are also called helping verbs, helper verbs, or (verbal) auxiliaries. Research has been conducted into split inflection in auxiliary verbs. Below are some sentences that contain representative auxiliary verbs from English, Spanish, German and French, with the auxiliary verb marked in bold: These auxiliaries help express a question, show tense/aspect, or form passive voice. Auxiliaries like these typically appear with a full verb that carries the main semantic content of the clause. Auxiliary verbs typically help express grammatical tense, aspect, mood, and voice. They generally appear together with an infinitive.