Odd and Useful English Expressions.

Today's odd and useful English expression is "teach grandma to suck eggs," which, apparently, is not as nasty as it sounds.

According to World Wide Words, it implies wasting one's time on a silly endeavor:

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 according to this site, this idiom implies teaching someone with more experience something they already know:

teach one's grandmother to suck eggs


Fig. to try to tell or show someone more knowledgeable or experienced than oneself how to do something. Don't suggest showing Mary how to knit. It will be like teaching your grandmother to suck eggs. Don't teach your grandmother to suck eggs. Bob has been playing tennis for years.

See also: egg, suck, teach

Urban Dictionary offers:

Teaching some process which should already be known, especially to a person who should already know it.


"What does this woman think she's doing? Teaching multiplication to a Calculus class is like teaching grandma to suck eggs!"

It's an expression that Robert A. Heinlein used periodically. I was curious where it came from.