The grammar vigilante at work. Picture: BBC

He calls himself the grammar vigilante and, in time-honoured superhero tradition, a man in the British city of Bristol hides his true identity as he works under the cover of darkness, to banish the streets of errant apostrophes.

A sign bearing a misplaced apostrophe targeted by the grammar vigilante.Source:Supplied

By night, armed with a homemade tool he has labelled an apostrophiser, the grammar vigilante, with his heart pounding, sticks tape over public signage bearing incorrect grammar.

But he denies he is committing a crime.

In an interview with the BBC, the man labelled the Banksy of grammar maintained he was fighting the good fight, as he had done for the past 13 years.

On his one-man mission to improve grammatical standards.

“It’s more of a crime to have the apostrophes wrong in the first place,” he told the British broadcaster.

In time-honoured hero tradition, the grammar vigilante has chosen to hide his true identity.Source:Supplied

“I have felt extremely nervous, the heart has been thumping.”

By day, the grammar vigilante’s true identity remains a mystery.

But he maintains he is working in the public interest.

“I do think it’s a cause worth pursuing,” he said.

“I don’t think it’s damage. What I’m doing is sticking on a bit of sticky-back plastic.

“It’s a worse crime to have all these errant apostrophes on shops and garages.

“I just think it’s going to teach the youth of tomorrow the wrong grammar.”

The grammar vigilante. A real-life incarnation of Apostrophe Man?Source:Supplied