Mike Kent is a Friday columnist and head of Comber Grove primary school in the south London borough of Southwark
"This is more of a secondary problem than a primary one - or, at least, it should be. Swearing should be one of those low-tolerance issues; in any school with a strong ethos and clear codes of behaviour, it will be. I rarely hear a child swear, apart from first thing in the morning when the children play football in the playground and an expletive or two drifts up to my room. Even that is rare, because every child here knows how we feel about it. But a certain amount is to be expected, given the behaviour they witness from footballers.
"Playground fights involving bad language are rare too, but just occasionally a child will become so irate a phrase or two of colourful language will be aimed at an opponent. Even so, it will rarely happen in front of a teacher, and only occasionally in front of a playground supervisor.
"It's taken years to get the sort of standard we want, and, with appalling language all around us, there's every temptation for children - and parents - to use it frequently. We need to show that it doesn't shock us, that it's tedious, juvenile and unnecessary.
"It's essential that a similar standard of behaviour is expected of every teacher. Children must know where they stand. It gives them security and they actively seek this, especially as so many of them don't have it at home."