What about that phrase ‘till the cows come home’? Why don’t people just say what they mean, which is either ‘forever’ or ‘for an indefinitely long time’?
The question answers itself in a flash. Till the cows come home, like many metaphors, adds colour, emphasis, atmosphere, even a bit of pizzazz. How dull and dreary communication would be if we just stuck to the literal and used words like Lego blocks, clunkily building up our sentences word-brick by word-brick. Till the cows come home certainly chimes loudly enough with the British public to turn not one but two books with that title into Sunday Times bestsellers this year.
And not only that: if you tend to ‘see’ words and phrases, it adds a vivid image. For me it evokes the sight of dappled Guernseys ambling along a muddy path towards the byre or milking parlour, their brimful udders swaying pendulously. For painters of the Dutch Golden Age specializing in landscapes (a word English nabbed from Dutch), cows munching contentedly in their pastures or standing stolidly near a river were a symbol of hard-won tranquillity and prosperity after an almost century-long struggle for freedom.
What do you see?
Sometimes till the cows come home conveys that simple meaning of ‘indefinitely’, with no other implication or connotation, and can even be used in a positive, upbeat context:
So eat them [sc. olives] till the cows come home in pubs or restaurants to help take the edge off your appetite.
Much more often, however, we use it to highlight the futility of some action, to suggest that it is against all odds for an event to happen. It’s often associated with talking and verbs in the same lexical field, such as debating, arguing, and so forth. The idea is of an endless ‘talking shop’:
The debate on whether the death penalty must be abolished or not will go on till the cows come home.
You could argue about it till the cows come home – and Kiwis frequently have.
Perhaps I m just embittered by experience, but I think most teenagers have been a pain in the bottom since their invention decades ago. One can pander till the cows come home, but it won’t make a scrap of difference.
But why cows in the first place? And why home? Except in the deepest depths of winter, most dairy cows in Britain will be let out to graze on grass and pasture. In high summer, they can be outdoors for most of the day, from early in the morning – with an interval for morning milking – until it’s time for milking again in the early evening. That makes for a long day and thus motivates, even nowadays, the idea of an endlessly long stretch of time.
‘Home’ historically must have been a byre or milking shed. And in the past, the cows might be left out all day, or even overnight, until ready to be milked. That, at least, is one explanation for the phrase. In its favour, the ponderous, unruffled, almost languid way in which cows walk can, from a human perspective, slow down time almost to a standstill. Think the spondee of the lowing herd wind slowly o’er the lea and the long vowels and diphthongs in the rest of that line.
Another explanation mooted is that the period of time evoked refers to the whole of the summer, when cows in Scotland were put out to pasture, returning home only when grazing became scarce at the end of the season. This, however, seems to be based on the unsubstantiated claim that the phrase is Scottish, as reported in the Times in January 1829:
If the Duke [sc. of Wellington}will but do what he unquestionably can do, and propose a Catholic Bill with securities, he may be Minister, as they say in Scotland “until the cows come home”.
Whether the phrase was originally Scottish, who can say. The claim is probably fake news. What is certain is that it is first recorded in plays by the Elizabethan stage’s Ant and Dec, those sub-Shakespeares Beaumont and Fletcher.
In fact, originally only one methane polluter was involved because the idiom was: till the cow come home. And in case you’re wondering whether that verb form come is a misprint, it isn’t. It’s the subjunctive being used with reference to future time, just as it is in come what may (= whatever may occur in the future) and the now decidedly old-fashioned till kingdom come, which echoes the Lord’s Prayer thy kyngdom come. Thy will be done.
In contrast to typical negative modern uses, in both B&F plays –– the activities to be indulged in till the cow come home are pleasurable:
Kiss till the Cow come home, kiss close, kiss close knaves.
My Modern Poet, thou shalt kiss in couplets.
Good morrow! Drink till the cows come home, ’tis all paid, boys.
That B&F used the phrase twice suggests it was already well known at the time they wrote; this is supported by another 1610 quotation, from Alexander Cooke’s extreme Puritan rant Pope Joane: a dialogue between a papist and a protestant, in a passage in which priests are accused of all manner of libertinage:
…he [sc. the Priest] conforts with his Neighbour Priefts, who are altogether given to Pleasures; and then both he, and they, live, not like Chriftians, but like Epicures; drinking, eating, feafting, and revelling, till the Cow come Home, as the Saying is.
Cooke’s diatribe is in Latin and English; the Latin matching ‘till the cows come home’ is the bland Tempora tota consumunt (‘they spend all their time’). Clearly, using his native tongue enabled him to ride high on his hobby horse. In an earlier section he foams at the mouth thus: So that now it is all one, to make a Wench a Nun, and to make her a Whore.
Mother Teresa would turn in her grave.
The first modern version noted by the OED is from Swift’s A Complete Collection of genteel and ingenious Conversation (1738):
I warrant you lay a Bed till the Cows came Home.
The most up-to-date quotation I found in the news is a review from Digital Camera World Magazine which uses the phrases in its positive, Jacobean sense:
 1610, Scornful Lady; 1609–12, The Captain.