Parents at a primary school in Middlesbrough have been sent a letter from the head teacher advising them on correcting their children's Teesside accents.
Pupils at Sacred Heart Primary School have been sent home with a list of 11 words or phrases which can cause problems with grammar or pronunciation.
While some can trip up any child from John O'Groats to Land's End - such as the difference between "your" and "you're" - others are particular to the region.
Head teacher Carol Walker has placed the word "Yous" firmly in detention, explaining "the word you is NEVER a plural", and she has asked parents to pick up on the pronunciation of work (not "werk") and shirt (not "shert").
Children growing up around Middlesbrough do not speak Geordie, and some elements of the Teesside accent sound more like Scouse.
"Letta" and "betta" end with an "-er", she stressed, and she pointed out school ends at "three fifteen", not "free fifteen".
Mrs Walker, who was born in nearby Stockton and has been head at the urban primary for 12 years, stressed the aim was not to wipe out the Teesside accent but to teach children standard English.
She wanted pupils to avoid being at a disadvantage in later life, especially in the jobs market, where those who cannot communicate clearly can struggle. To back up efforts at school, she decided to write to parents asking for their help at home, and the response has been "really positive".
"We have not had any negative reaction at all," she said. "It's about knowing when it is appropriate to use one voice rather than another.
"I am not asking children to deny where they come from, I am saying to them there are certain situations where they need to be able to use standard English."