Fam, imagine if man said you couldn't use words like "peng", basically and "dem tings dere" in your classroom.
Didn't understand any of that?
This might be because you were born in a different generation.
Just imagine if you were not allowed to use slang words that meant "beautiful" or "lots" when you were in school.
That is the case for some students, who are being urged to ditch slang words in lessons in order to teach them how to use formal English.
In fact, some schools have even introduced anti-slang posters and stickers, grammar police badges and word jails, where slang is written on posters with jail images.
Does that mean that pupils studying there have to tell their classmates they look "jolly well splendid" rather than a "peng ting"?
However, a linguistics expert is warning that slang bans may actually cause more harm than good.
"There's no incorrect or correct way of using language," says Ian Cushing, a lecturer in education at Brunel University London.
He carried out a study by visiting schools and speaking to teachers in England over a year and found examples of slang being banned and policed in lessons.
These included words such as "peng", "bare" or abbreviations such as "emosh" for emotional.
There were slang bans at about 20 of the schools he visited, which were mostly located in urban areas.
"Language is just one part of your identity - just the same way you wear your hair and clothes," said Dr Cushing.
"Young people will police their own language - they don't need other people to police it for them, they understand the context of their situation, and know when to shift it accordingly.
"Shakespeare is full of slang and we don't see teachers banning that - there's a hypocrisy here, which is rooted in cultural and linguistic snobbery."
Do you know these slang terms?
- Peng = someone who is good-looking
- Bare = lots of or a large amount of
- Fam = short for family or a close friend
- Bruv = short for brother
- Bait = when something is blatantly obvious
- Calm = no problem
The linguistics academic says slang is a natural way of speaking, and banning it may be a threat to a person's identity.
It may also make students feel discriminated against and less motivated to take part in lessons.
"Young people are typically the innovators of language change, so actually we should be celebrating that rather than banning it in the classroom," said Dr Cushing.
Slang ban ain't the one
Francesca, a student at South Thames College, a further education college in Wandsworth, south-west London, says she is allowed to use slang in her lessons.
But the idea of a slang ban on students does not appeal to her.
"It's like taking away their voice in a way," says the business student, warning that young people might feel they were unable to "express themselves".
"I think it will end up driving more students to not want to communicate.
"I would probably end up getting in trouble for things that would slip out, not by purpose," she says, adding that a slang ban could stop students wanting to "interact" in the classroom.
Fellow student Tomas migrated to England five years ago and could not speak English.
He started learning slang in secondary school and now uses it with his friends.
"I think if slang was banned in primary or secondary, it would be understandable, because that's when children are growing and start listening to slang," he says.
"On one hand I think it should be banned, because it will help children and young adults to learn and be prepared for the working world. But banning it can also mean that the freedom of speech for some people can be affected."
Another student, Imran, says: "If my teacher told me that I cannot use slang words, I will feel a bit uncomfortable, mainly because it's not harming anybody.
"Slang is something that I've grown up with and it's just something that I wouldn't be able to finish the sentence with, without using it.
"There are cultures that use slang as a language, and if it's being stopped, they wouldn't be able to communicate with people the way they previously did when slang was involved."
Maybe using slang in school ain't that bad after all, innit?
However, other people argue that a slang ban is indeed necessary.
Chris McGovern, chairman of Campaign for Real Education, says allowing slang is not doing any favours for underprivileged children.
He says they are left in an "employment gutter" because of their "linguistic impoverishment".
"Nurturing street slang is fine for linguistic acrobats such as Cambridge graduate Sacha Baron Cohen's alter ego, Ali G," he says.
"It is much more difficult for that 20% of school leavers who, according to employers' organisations, are largely unemployable because of poor literacy.
"In the UK today, around nine million adults are functionally illiterate, and many of them suffer under-employment, unemployment or destitution as a consequence."