Parents have branded a West Midlands primary school 'snobbish' and 'insulting' after it introduced an initiative to make pupils speak proper English instead of the Black Country dialect.
Kids who say phrases such as 'cor do that' – 'can't do that' – will be corrected every time they utter an outlawed word.
Colley Lane Primary School in Halesowen says the 'zero tolerance' policy will raise standards.
A letter posted to parents last week said: "Recently we asked each class teacher to write a list of the top ten most damaging phrases used by children in the classroom. We are introducing a 'zero tolerance' in the classroom to get children out of the habit of using the phrases on the list."
The Black Country includes Dudley, Sandwell, Walsall, and southern parts of Wolverhampton. Other words and phrases on the prohibited list include 'ay', meaning 'pardon', and 'I day', meaning 'I didn't'.
Alana Willetts, 30, whose nine-year-old son George goes to the school, said staff should be teaching pupils about the Black Country and its dialect.
"Some of my friends have gone on to be doctors and lawyers and I'm an engineer – [the accent] doesn't affect you as a person," she said.
"I think it is patronising and insulting to say that people with a Black Country accent are disadvantaged. All the parents are outraged."
Ann Mills, 62, who has two grandchildren at the school, added: "I was raised here and I'm proud of the way we speak."
But Zheyan Kareem, 31, who moved to the UK eight years ago and whose seven-year-old son is a pupil, supported the ban, saying: "English is my second language. So for me ... it is good if my child speaks English in the house and not slang picked up at school."
Head teacher John White defended the move, saying: "We value the dialect but we want to encourage children to learn when to use it and when not, like for a job interview.
"I think we are seeing a decline in standards of English when children come into school. We are seeing that some children coming in are not able to speak very much at all to be honest.
"I think some of the changes in society - the amount of time people sit around and talk together and the amount of screen time - seem to be having an effect on how confidently children speak when starting school.
"We want to pick them up on that and improve their standards in English. It is important because it is the foundation of everything.
"If they can't say it, it is likely they can't read it, and even less likely they can write it."
The banned phrases
1. 'They was' instead of 'they were.'
2. 'I cor do that' instead of 'I can't do that.'
3. 'Ya' instead of 'you.'
4. 'Gonna' instead of 'going to.'
5. 'Woz' instead of 'was.'
6. 'I day' instead of 'I didn't.'
7. 'I ain't' instead of 'I haven't.'
8. 'Somefink' instead of 'something.'
9. 'It wor me' instead of 'it wasn't me.'
10. 'Ay?' instead of 'pardon?'