Teaching grandmother to suck eggs

Teaching grandmother to suck eggs is an English language saying meaning that a person is giving advice to someone else about a subject of which they are already familiar (and probably more so than the first person).

The origins of the phrase are not clear. The OED and others suggest that it comes from a translation in 1707, by J. Stevens, of Francisco de Quevedo (Spanish author):

"You would have me teach my Grandame to suck Eggs"

“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 what am I about? If my grandmother sucks eggs, was it I who taught her?”

The use of the phrase "Suck-egg" for "a silly person" dates back to 1609, in the OED.

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