Here we have the Catnach broadside of 'Banks' with the differences of an (oral tradition version) alongside.

As I walked out one midsummer morning
(For) To view the fields and to take the air
Down by the banks of the sweet primroses
There I beheld a most lovely fair.

Three long steps I took up to her (I stepp-ed)
Not knowing her as she passed me by
I step'ed up to her, thinking (for) to view her
She appeared to me like some virtuous bride.

I said fair maid where are you going
Or what is the occasion for all your grief (And what's the...)
I'll make you as happy as any lady (I will)
If you will grant me some small relief. (me once more a leave)

Stand off, stand off, you are quite deceitful (She said stand off, you are deceitful)
You've been a false deceitful man 'tis plain (You are deceitful and a false young man)
It's(It is) you that's caused my poor heart (for) to wander
(And) To give me comfort it is all in vain. (comfort lies all...)

I'll go down into (in) some lonesome valley
(Where) No man on earth shall there me find (there = e'er)
Where the pretty (little small) birds shall change their voices (shall=do)
At(And) every moment shall blow blusterous winds (shall blow=blows)

Come all you young maids(men) that go a courting
Pray give(pay) attention to what I say
For there's many a dark and cloudy morning (There is many a dark and a...)
Turns out to be a sun-shining day (shining=shiny)

Not exactly the language of a ploughlad. Such pieces derive from the many musical pastoral plays of the early 19th century but they first hit the streets in the form of a broadside. The many broadside printings are pretty much verbatim the Catnach piece and oral versions deviate from this about as much as the version given above. There shouldn't be any reason to give the oral version's source, but suffice it to say Jon Dudley would recognise it straight away.