Can the word “go” be used as a helping verb?

For instance:

“Go eat your dinner.”

It appears that the word “go” is being used as a helping verb. Is it being used a helping verb? If so, can “go” only be used as a helping verb in imperative sentences?

Solution 1:

It is a usage of the verb go that is followed by the 'plain form' (or bare infinitive form) of another verb. The idea is

To move, travel, or proceed (to somewhere) so as to perform a specified action, or for the purpose of a specified or implied activity...(often with the sense of movement weakened)

(Oxford English Dictionary, OED)

The OED labels this usage as (nowadays) "colloquial" in North America and nonstandard in British English. It gives examples of this construction as far back as Old English. An example from Early Modern English comes from 1591, Edmund Spenser:

Now thou maist go pack.

which means "Now you may go pack."

Jane Austen wrote in 1813:

Your Streatham & my Bookham may go hang.

It is not always used as an imperative phrase, as

You wanna go see a movie?

shows.

The same construction is also found in such "imprecatory phrases" (OED) as

go fly a kite
go take a flying leap
go jump in a lake
go f**k yourself

and even

go figure

NOTE also that in the USA (apparently not nowadays in the UK) we use the verb come in a similar fashion to idicate "an action or activity which is the consequence or purpose of movement," as these OED citations show:

from about 1375:

He praide ȝou com speke wiþ him.

which means

He prayed(?) you come speak with him.

And about 1616 (Shakespeare):

Quicke, quicke, wee'le come dresse you straight.

(Quick, quick, we'll come dress you straight.)

and 2007:

I have half a mind to call the men in white coats to come take you away.

(Tamar Myers, Hell hath No Curry)