Marcel Hirshman holds two hands horizontally in front of him and sweeps them together repeatedly. “That can mean ‘arrangement’,” he says. “But it can also mean ‘having sex’. And there’s a third meaning: in American Sign Language, it can also mean Coke. Because the signs are so similar, there’s always a chance you could be misunderstood.” So I could try to order a drink and wind up getting more than I bargained for? “If you were lucky,” says Hirshman with an impish sidelong glance.

But Hirshman insists that signing has many advantages over spoken English. “For hearing people, it’s rude to point. In signing, it isn’t – it’s part of our language structure. It’s more economical and more specific.” He gives me an example. “In English you might say: ‘The newspaper is on the table.’ But which table? In sign language, I’d point at the table and sign ‘newspaper’, so you know immediately where this is.”

Hirshman, 36, is an intriguing guide through some of the droller corners of sign languages and how they differ from spoken languages. He is the son of deaf parents and is married to a deaf partner and has two children who are not deaf. Rosabella is two and Olivier is soon to be one. “My daughter has started to sign more and more complicated sentences. Some people say, ‘What about her speech, what about her vocabulary?’, but I don’t care about any of that. When she’s out of the house or when she’s watching TV, she’ll pick up English. It’s not a problem.” What was Rosabella’s first word? “Mummy, of course! She signed it. Olivier recently signed his first word, which was ‘Daddy’. I liked that.”

During our conversation (which is mostly conducted with Hirshman signing to an interpreter), he shows me a few signs for British towns. Peterborough, for example, is signed by brushing one’s finger over one’s nose – an allusion to the nickname of the town’s football club, the Posh. Derby is signed by drawing your hands in spiral motions around your temples – the nickname for Derby County FC, you see, is the Rams. Sheffield, venerable heartland of British steel manufacture, is signed with fingers simulating knives.

Disappointingly, Manchester isn’t signed by adding the sign for “man” to the sign for “chest”, but by finger-spelling M and C. Similarly, Newcastle isn’t signed with “new” and “castle” but by finger-spelling N and C. How is London signed? Hirshman circles one ear with his index finger, which I take to be the universal sign for madness. But it isn’t. “I think it originated because in London women wore hats with bows tied around their throat. So originally the same gesture was made at the level of the throat. Now it’s higher, around the ear, and indicates that London is noisy.” Perhaps the most bizarre sign for a town name, though, is for Preston, which Hirshman signs with a gesture signifying a priest’s collar.

“For a long time there weren’t really deaf signs for towns because there wasn’t much travelling,” he says. “Now if someone asks where you’re from, it’s not enough to use the sign for ‘here’.”

British Sign Language (BSL) is the preferred language of 50,000 deaf Britons and involves the use of both hands to sign, as well as very developed facial expressions and body language. But not all national sign languages are like this. “American Sign Language is horrible to me because there’s hardly any facial expression,” says Hirshman. “It’s all done with the hands. But for me facial expression is so important in expressing what I mean. If, say, I want to tell you, ‘I like a car’, in signing I’d say it by going, ‘Car, like’ – and ‘like’ would be expressed in this way . . .” He nods his head slowly, sticks out his lips and raises his eyebrows suggestively. I get what he means very quickly.

It’s often more economical than English: for example, hearing people will sometimes describe who was speaking in a conversation by saying “he said, she said”, but in sign language this can be communicated simply by shifting one’s shoulders to indicate who was talking. “Irish Sign Language, American Sign Language and lots of European ones use only one hand for finger-spelling, while BSL uses two.” It’s strange, I tell Hirshman, for an English speaker to find out that BSL is not closely related to Irish or American sign languages. ISL, intriguingly, is hardly related to English at all, but influenced very heavily by French Sign Language. BSL’s closest relatives are Australian Sign Language (known as Auslan) and New Zealand Sign Language (NZSL). Together, they form a family called BANZSL.

Even more unexpected are the regional variations within BSL. “In most of the country, ‘car’ is signed like this,” says Hirshman. He holds up two fists, at 10 o’clock and 2 o’clock, and wobbles them slightly – the steering wheel of a moving car. “But in Newcastle, it’s signed like this.” Hirshman holds his hands in the same positions, but with the thumbs and forefingers of each hand together and extends the other fingers horizontally. To me, I tell Hirshman, that looks like you’re offering me a fight. “That’s what I think it looks like, too. But in (Newcastle) that’s how it is.” Then Hirshman shows me how they sign “news” in Yorkshire, in the north of England, and how they do it in the rest of the country, and lots of other regional differences in BSL – they include the signs for evening, afternoon, football and rugby. “About 80 per cent of BSL is unified,” he explains, but the rest is regional. “It’s like you [British hearing people] say ‘bath’ differently in different parts of the country.”

Like anyone trying to learn a foreign language, I want to know how to swear in BSL. “I think all our swear words are very similar. We don’t really have any of our own, just signings of English.” He shows me the signs for some swear words. They are quite graphic, though not as rude as I had hoped.

And then Hirshman shows me the sign for a certain swear word, holding two cupped hands in front of him and letting them dangle heavily, accompanying the gesture with a sardonic look of disbelief. I had picked up the meaning without the interpreter translating. Indeed, during the interview a lot of the direct interaction between Hirshman and me involves eye contact and facial expression – which makes the experience strangely, though hardly unpleasantly, intimate.

Translating English into BSL is a tricky business, as Hirshman has found in his career as a TV signer for hit programmes such as the Catherine Tate Show. How, I ask, Hirshman, do you sign the catchphrase “Am I bovvered?” He shows me: it’s hard to convey in print, but very funny.

Hirshman tells me he is aware that deaf signers on TV are exasperating to some people. “Hearing people think: ‘Who is this person standing in front of the programme I want to watch?’ And deaf people often think: ‘The signer should be in the programme rather than outside it.’” So you’re resented by everyone? Hirshman gives me the impish sidelong glance again – I don’t think he minds too much.

BSL was recognised by the UK government only four years ago, after centuries in which the language was virtually ignored officially. “We were so very grateful,” says Hirshman, dryly. “Actually, it hasn’t made much difference in practice. What has made a difference to us is the Disabilities Discrimination Act. That has resulted in things like this.” Hirshman produces from his bag a DVD of the Highway Code designed for deaf people. What was wrong with the written Highway Code? “Our preferred language is BSL, not English. We were being discriminated against.”

But that makes the deaf community sound less like a disability group and more like beleaguered speakers of a minority language, like Welsh or Gaelic, I suggest. “Exactly. Actually, we’ll use both – our disability status and our minority cultural status – to help ourselves. But you’re right: we are often more like a disadvantaged cultural minority than anything else.”—Dawn/Guardian News Service