If you tiptoe around a delicate subject or try not to anger a touchy person, are you walking on eggs or walking on eggshells?
Walking on eggs is a perilous business. It's conceivable that having enough eggs underfoot could support the weight of a small person without cracking, but please do not write me to tell me that you have tried this experiment, that your shoes have been ruined by yolks and that you will hold this column responsible. This isn't Quirks and Quarks.
The point is that treading softly to avoid crushing eggs is a good metaphor for proceeding warily. The Oxford English Dictionary traces the expression "tread upon eggs" back to the 1700s, when someone named Roger North wrote: "This gave him occasion ... to find if any slip had been made (for he all along trod upon eggs)."
Its use continues. In April, The Jerusalem Post quoted a judge's ruling that certain rights should be infringed only "under special circumstances and with utmost care, as though one were walking on eggs." In the same month, singer Marie-Jo Thério told the Montreal Gazette that she "became terribly aware of the fragility of these cousins and uncles, who were very real people, so it was like walking on eggs."
Walking on eggshells is a relative latecomer. The OED finds its first printed reference in the 1860 serialization of Wilkie Collins's novel The Woman in White. "With that woman for my enemy, I walk, in your English phrase, upon egg-shells."
To my mind, that variation is not entirely satisfying. Are the eggshells intact or broken? If they are intact, and assuming somebody's grandmother hasn't sucked out the innards (more about that in a minute), they are still eggs, so "walking on eggs" applies.
And if they are broken, why worry about walking on them? Who cares if you destroy shells that are already cracked? The noise might be irritating, but it's not as though you've deprived someone of breakfast.
Yet the evidence suggests that walking on eggshells is far more common today than walking on eggs. Examples are legion, including an Aug. 11 article in the Toronto Star ("Some lawyers appeared to be walking on eggshells") and an Aug. 1 concert review in The Globe and Mail ("There was a kind of 'walking on eggshells' care in their playing").
I promised to return to the mention of the grandmother. "To teach your grandmother to suck eggs" means to have the effrontery to instruct someone who knows the subject far better than you do. Grandmothers are apparently wizards at sucking the contents of an egg out through a hole, perhaps so they can decorate the now-lighter eggs. So much to learn, so little time.
Another curious expression, "as sure as eggs is eggs," dates from the 1600s and is still in circulation. British Prime Minister David Cameron used it last January in a speech in Newcastle. "But I recognize I've got a big job to do to get round the country and explain that to people, but I think if we do those things we will put the Great back in Britain as sure as eggs is eggs."
One school of thought says the expression has nothing to do with eggs and everything to do with mathematics. In algebra, x is an unknown variable. Edwin Radford, in Crowther's Encyclopaedia of Phrases and Origins, speculated that "as sure as eggs is eggs" was a corruption of the phrase "as sure as x is x." That would explain the singular verb, and the x in algebra did predate the first known printed use of the eggs phrase, but it's hard to imagine "as sure as x is x" seizing the popular imagination in the first place.
At any rate, think twice before stating it as fact. You'd hate to end up with egg on your face.