Italian equivalent

Teaching my grandmother to suck eggs

Since I'm a middle-aged native (American) English speaker and had never seen or heard this idiom in my entire life, you probably should have provided an explanation of its meaning, as it may be common in your part of the world, but certainly isn't in mine. However, I found an explanation here. It also shows up in Wiktionary with translations into various languages...but unfortunately Italian isn't one of them.

I'm sorry #1. It hadn't occurred to me that it might not be in use in the USA. It gets 200,000 finds on Google.

It means to tell someone how to do something that they already know. Which, of course, is always resented. In Portuguese it's "Ensinar o Padre-Nosso ao vigário." so I thought Italian might be something similar.

I tried "Insegnare il Padre Nostro al Papa", and "Insegnare la preghiera del Signore al sacerdote", but only found a few usages. This surprised me because I found 81,000 achados in Portuguese.

It's hard to believe there's no Italian equivalent.

It's a British idiom.

I don't speak Italian but this [web|cvc.cervantes.es/lengua/refranero/Ficha.aspx?Par=58094&Lng=8] suggests non si insegna a nuotare ai pesci. Not sure if it'll be exactly what you are looking for though. You can find more info about that Italian idiom at the bottom on this web.

I think that I must win some sort of prize, because I'm older than zashibis and thus hadn't heard the expression for an even longer time.

Briowsing the web, I found a few interesting examples of similar proverbs in various Italian dialects

"faga mia mpara al gat a rampa su la pianta" (Bergamo dialect: don't teach a cat how to climb a tree)

"oh tu voi insegnare il culo a cacare" (Florence dialect: are you trying to teach an ass*** how to crp)

In standard Italian, however, the only one seems to be the one about teaching the fish how to swim, as mentioned above, and I have to say it is not frequently used anyway (I for one had probably never heard that expression).

Italian is my mothertongue and I have been living in Italy since birth, but I have never heard those idiomatic expressions - not even the one in the Bergamo dialect, that is widely spoken around here.

Neither can I think of another sentence to match the English one, which I read here for the very first time.

I'm familiar with the phrase, but only in writing. I've never heard someone use it or seen it in informal writing (such as a forum post), except in a discussion of the phrase itself. I can't remember where I first saw it. Perhaps in an old British murder mystery or perhaps in a book about the English language.

Fielding used it in Tom Jones.+ The oldest citation seems to be a 1707 translation of +The comical works of Don Francisco de Quevedo. "You would have me teach my Grandame to suck Eggs."

The oldest version in English of the concept of trying to give advice to an expert is (from the Phrase Finder
>Nicholas Udall, the author of 'Ralph Roister Doister' the first regular English comedy, and the headmaster of Eton, translated The Apophthegmata in 1542 from the works of Erasmus. That includes:
>"A swyne to teach Minerua, was a prouerbe, for which we sai: Englyshe to teach our dame to spyne."

A Spanish-English forum posts says that the Spanish equivalent is "no le enseñes a hilar a tu madre." (Don't teach your mother to spin)

French ce n'est pas à un vieux singe qu'on apprend à faire la grimace (don't teach an old monkey how to make faces)

Not having luck with Italian.

Of course, I'm used to idioms not meaning what they appear to mean, but I have to say I was very surprised when I looked up the meaning for the second post in this thread. To this American, "to suck eggs" still sounds shockingly rude...not at all the sort of thing your granny would be doing...at least, not in public.