Q From Jonathan Downes: I wonder if you would care to explain a phrase in wide use but rather odd in its direct meaning: teaching your grandmother to suck eggs? (This has been in use by my parents, both in their 70s).
A It does look odd, but its meaning is clear enough: don’t give needless assistance or presume to offer advice to an expert. As that prolific author, Anon, once wrote:
Teach not thy parent’s mother to extract
The embryo juices of the bird by suction.
The good old lady can that feat enact,
Quite irrespective of your kind instruction.
Many similar expressions have been invented down the years, such as Don’t teach your grandmother how to milk ducks, and don’t teach your grandmother to steal sheep. These have the same kind of absurd image as the version you quote, which has survived them all. It was first recorded in 1707 in a translation by John Stevens of the collected comedies of the Spanish playwright Quevedo: “You would have me teach my Grandame to suck Eggs”. Another early example, whimsically inverted, is in Tom Jones by Henry Fielding, published in 1749: “I remember my old schoolmaster, who was a prodigious great scholar, used often to say, Polly matete cry town is my daskalon. The English of which, he told us, was, That a child may sometimes teach his grandmother to suck eggs”.
But the idea is very much older. There was a classical proverb A swine to teach Minerva, which was translated by Nichola Udall in 1542 as to teach our dame to spin, something any married woman of the period would know very well how to do. And there are other examples of sayings designed to check the tendency of young people to give unwanted advice to their elders and betters.