When do you use "do be" for emphasis?

Question

This question is about the do-support for emphasis.

I realize that do-support for emphasis is usually applied to ordinary verbs, not auxiliary verbs. (e.g., I do like apples.) Some grammar books say that do-support for be-verbs can be used only for imperative sentences. (e.g., Do be quiet.)

However, I found some examples of using do-support for be-verbs in usual sentences in some comic books or novels, basically in spoken language. An example is here.

A: "They do say that the Americas are home to thunder lizards, and huge leatherwings, and dragonish monsters."

B: "Aye. There do be such monstrosities there, Robert. And daggermouth lions, and hairy oliphaunts and more." (from a comic book)

I'm guessing this usage can be used in a spoken language though it is not grammatically correct, strictly speaking. Thus, my question is, (1) In what situation do people use "do be" for emphasis? (2) Are there any characteristics of people who often use "do be"?

If you have more detailed insights, I'd be happy if you kindly share it.

Answer 1

The Sentence of the Court [1913] by Fred M White [a prolific writer in the early 20th c.]
Published in The Sydney Morning Herald, Thursday, 4 December, 1913.

"I bean't up in these 'ere things, sir," James went on. "I'd never be one to make a fuss over a lot of painted calico, I wouldn't. How folks can give thousands of pounds for them 'ere picters fairly 'mazes me. Ay, and sometimes they gets what's called forgeries. There do be tricks in every trade 'sides horse-copin', it seems, sir."
[the "ay" suggests the speaker is Irish?]

Project Gutenberg_Australia

The Ragged Edge

“I’ll go till the convintion mesilf,” answered McGlory. “There do be too damn much of this proxy business.”
“There do be a good profit in tay,” put in the grocer, who was now sitting up, having his hair brushed; “but how he iver made all av the property he’s left, be peddlin’ it from dure till dure, gits the better av me.”
>“Ayther that or till Mary Carroll. Kelly t’inks there do be a chance for his boy, Martin; but Martin’s a hard drinker an’ the owld man niver liked a bone in his body.”
“May the divil fly away wid Clancy’s wife an’ her silks as well! Faix an’ there do be other things that Clancy could do wid his money!” O’Hara was in a stormy mood. Ellen scraped up the sweepings. “There do be bad luck enough about the place,” she continued, as she slid the dust into the fire and watched it burn, the flame lighting up her old, faded face, her dirty white cap, her bony, large-veined hands. “Malachi tells me that the biz’ness do be poorly.”

In 1898, he started writing his first novel, a political drama set in the wards along the Schuylkill River and Philadelphia waterfront, titled The Ragged Edge. The only copy of his manuscript was stolen during an express company robbery and it took him nearly a year to rewrite the book from memory. The book was published by McClure, Phillips in 1902 and is now considered an early example of the urban Irish-American political novel.
McKintyre _ Wikipedia

John McIntyre Release Date: November 17, 2022 [eBook #69373]

Gazing out over the small, cliff-sheltered harbour with its stone quay to the blue sea and sky beyond, he said, “There do be a storm a-brewin’ out yonder, my lover. Gales afore mornin’, you mark my words. Don’t ’ee go to sea.” [Cornwall, 1960's_Cornish English]

Buried in the Country

Do+Be

[...]Different scholars use different terms for this grammatical feature, including habitual, durative habitual, iterative, consuetudinal and generic aspect, ‘often with very subtle subdistinctions’ according to Markku Filppula. [...]

In the Irish language (but not in English) there is what is called the consuetudinal tense, i.e. denoting habitual action or existence. It is a very convenient tense, so much so that the Irish, feeling the want of it in their English, have created one by the use of the word do with be:
‘I do be at my lessons every evening from 8 to 9 o’clock.’
‘There does be a meeting of the company every Tuesday.’ ‘’Tis humbuggin’ me they do be.’ (‘Knocknagow.’)

Sometimes this is expressed by be alone without the do; but here the be is also often used in the ordinary sense of is without any consuetudinal meaning.
‘My father bees always at home in the morning’: ‘At night while I bees reading my wife bees knitting.’ (Consuetudinal.)
‘You had better not wait till it bees night.’ (Indicative.)

do be habitual in Irish English [Bolding mine]

do be or does be is Irish English and spoken. It's found in the writings by some of Ireland's famous writers like: James Joyce, Edna O'Brien and John Synge.

Here is a truly marvelous example with do be + present continuous from Synge quoted in the blog cited above. And it is taken from the Irish language:

For it’s a raw, beastly day we do have each day, till I do be thinking it’s well for the blind don’t be seeing them gray clouds driving on the hill, and don’t be looking on people with their noses red, the like of your nose, and their eyes weeping and watering, the like of your eyes, God help you, Timmy the smith. [Beautiful, that!]

Answer 2

I suggest the Question largely confuses the less common use of 'do' for emphasis with the more frequent use in confirmation, because it makes no distinction between questions and answers.

That's because 'do' is rarely used for emphasis and far more often in simple confirmation, or in contra-distinction.

'They do say…' isn't for emphasis; it usually shows confirmation, as opposed to introduction.

Consider Tommy Atkins sitting in a pub. He will normally introduce a fresh topic of conversation with 'They say…' and only irrelevantly rarely with 'They do say…' - unless this isn't general English but a local dialect, as with OutstandingBill's Bristolians.

Normally, only when Joe Soap has launched into 'They say…' will Tommy respond with 'They do say…' and if he does, that's just as likely to lead into '… but they're wrong' as '… and they're right'.

If this was about emphasis, Joe would use 'They do say…' only in agreement. In argument, he would more likely use 'They say, but…'

'There do be…' fails in the same way.

Broadly, characteristics of my British people who often use 'do be' would be simply that they were somewhat rural and unsophisticated… which, no, is not a euphemism for 'country bumpkins.' Consider for instance, OutstandingBill's Bristolians.