Pupils should stop calling their teachers 'Sir' and 'Miss' because the titles are sexist, says academics.
They say the titles are old-fashioned, demeaning to women and should be replaced by either Mr and Ms or even by first names.
The call is reported in the the Times Educational Supplement.
One academic, Jennifer Coates, emeritus professor of English language and linguistics at Roehampton University, said: "It's a depressing example of how women are given low status and men, no matter how young or new in the job they are, are given high status.
"Sir is a knight. There weren't women knights, but 'Miss' is ridiculous: it doesn't match 'Sir' at all. It's just one of the names you can call an unmarried woman."
Instead, she said pupils should be encouraged to use teachers' first names to bring schools up-to-date and ensure children are not exposed 'to the prejudices of the previous generation'.
The titles, which have been used by generations of British schoolchildren, can be traced back centuries.
'Sir' was first used in 16th century classrooms when male teachers of a lower social standing were attempting to reinforce their authority among largely upper-class boys.
'Miss' is largely a throwback to the late Victorian era when pressure was put on women to give up work after they married, with a number of schools only hiring single female teachers.
Education historian Jacob Middleton told the TES that both titles were 'old-fashioned' and 'embody the massive status disparity and sexism of former years'.
And Robin Lakoff, professor of linguistics at the University of California, Berkeley, in the US, said the traditional title for male teachers 'always conveys respect' while Miss does not.
She said: "It's very hard to create linguistic equality between people who, in many people's minds, aren't equal.
"At school, we have children who are still really only learning language. They pick up on it very readily and then the next generation gets exposed to the prejudices of the previous generation."
She said schools should scrap the titles and call all male teachers Mr followed by their surname, while female teachers are called Ms.
But Professor Sara Mills, from the Humanities Research Centre at Sheffield Hallam University, said schools should go further by reverting to first names.
She said: "Sometimes teachers find that they can control students more when they try to stress the similarities between them, rather than trying to keep as distant as possible."
However, one school leader insisted the traditional titles should remain because they show respect.
Debbie Coslett, chief executive of the Brook Learning Trust, which runs three schools in the south-east, told the TES: "If I'm in a school where students don't know me and they call me 'Miss', I'm fine with that.
"They're showing respect by giving me a title rather than 'hey' or 'oi, you' or whatever.
"Sir is a term you might call a man. You wouldn't call anyone Mrs or Lady or Dame. That's just the way the English language works."
What do you think? How do your children address teachers at schools?