A triumph, then, for those who never thought it at all paradoxical to be so formal and simultaneously so forward when inquiring, as the song goes: “Voulez-vous coucher avec moi ce soir?”

For France’s newly installed Government has decreed that it is time for a renaissance of linguistic (and thus social) formality and civility; at least in the classroom. Pupils are being instructed to address their teachers as “vous”, so stifling a swing towards the use of the familiar “tu” among younger generations, who have come to regard the word “vous” as old-fashioned, uncool and out of tune with today’s dress-down-Friday, first-names-only mood of unbuttoned informality.

Englishmen untutored in the finer points of French grammar might grasp blindly for “tu” or “vous”, the way they might reach for a tie in the dark, thinking it matters little which of the two they use so long as they make their point. But to French ears the difference between addressing someone as “tu” or as “vous” is as potently audible as the musical shift that prompted Cole Porter, in Every Time We Say Goodbye, to reflect on “how strange the change, from major to minor”.

Few faux pas are clumsier than using “tu” when “vous” is more appropriate, as François Mitterrand showed when a Socialist colleague suggested they use “tu” to one another, to which the President frostily replied: “Si vous voulez.”

Killing off “vous” has proved tougher even than killing off crab grass. In the egalitarian wake of the French Revolution, the use of “vous” was banned in the French administration on pain of prison. But Jean-Paul Sartre and Simone de Beauvoir, liberals both, were always “vous” to each other. God is addressed as “tu”. C’est la vie.