Auxiliary Verbs

English

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.

Auxiliary verb	Meaning contribution	Example
be1	copula (= linking verb)	She is the boss.
be2	progressive aspect	He is sleeping.
be3	passive voice	They were seen.
can1	deontic modality	I can swim.
can2	epistemic modality	Such things can help.
could1	deontic modality	I could swim.
could2	epistemic modality	That could help.
dare	deontic modality	I dare not attempt it.
do1	do-support/emphasis	You did not understand.
do2	question	Do you like it?
have	perfect aspect	They have understood.
may(1)	deontic modality	May I stay?
may(2)	epistemic modality	That may take place.
might	epistemic modality	We might give it a try.
must1	deontic modality	You must not mock me.
must2	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.
should1	deontic modality	You should listen.
should2	epistemic modality	That should help.
will1	epistemic modality	We will eat pie.
will2	future tense	The sun will rise tomorrow at 6:03.
will3	habitual aspect	He will make that mistake every time.
would1	epistemic modality	Nothing would accomplish that.
would2	future-in-the-past tense	After 1990, we would do that again.
would3	habitual aspect	Back then we would always go there.