Eleven-year-old Marine Tessier has just spent her first Christmas in England, playing games and watching English television. Yet five months ago, when she came to stay with the Muncaster family in Oxford, she could barely speak a word of English. Since then she has been immersed in it. “Marine can now follow anything,” says Susie Muncaster. “It’s remarkable.”

Every year a handful of British families take part in an unusual six-month exchange with their French counterparts. In February Isabel Muncaster, also 11, will go to Bordeaux where she will stay with Marine and attend a French school. She will be known as Isabel Tessier.

It might seem a drastic step. But language learning in Britain is notoriously patchy, and, thanks to the world dominance of English, is likely to stay that way — despite the government’s recent decision that every 7 to 11-year-old should be given the chance to study a European language.

Under the government’s proposals teaching assistants will be drafted in from businesses to help out in primary schools. Yet the lessons will not form part of the national curriculum and will not be compulsory. Meanwhile, secondary school pupils have been allowed to abandon languages at the age of 14.

Until the scheme has been operating for a while nobody knows how effective it will be. In the past parents with children in state primary schools have made their own arrangements for language learning.

One increasingly popular choice has been to sign up for lunchtime lessons provided in state schools by private companies. Parents pay about £5 a week so their child can get extra lunchtime teaching in a group.

But take care before you part with any cash, says Christine Haight, who runs Native French Teachers (NFT, www.frenchtuition.co.uk). Haight holds half-hour lunchtime lessons at 23 schools around London and the southeast. But she does not think they are particularly effective.

“The students are not terribly committed,” she says. “Teachers coming into a school for half an hour a week get very little respect. They are often more concerned with discipline than teaching, even with the younger children.”

Private individual lessons are probably more effective, though more expensive. NFT, for example, charges £29 an hour, with some pupils starting at the age of four.

Marie Atallah, in Wimbledon, south London, pays for her four children, including a seven-year-old, to have half an hour of individual French tuition a week from NFT.

“I’m disappointed with the teaching of French at school,” she says. “It’s non-existent at primary. At secondary the teaching is unstructured and poor. It’s just not being taught to the standard it should be.”

Now, after a couple of months, she says the tuition has made “a huge difference”. Joseph, 7, can already hold a basic conversation.

Total immersion is probably the most efficient method of language learning, although children need to be confident. The Muncasters arranged their exchange with Marine Tessier through a French firm, En Famille International (www.enfamille.com) at a cost of about £500. They are so impressed that they are considering sending another daughter, Josie, aged just nine.

“A lot of people think it strange to send a child away for six months at that age,” says Susie Muncaster. “But we view it as an opportunity.”

Paula Spangenthal and her husband Mark enrolled their daughters at a French-speaking primary in Ealing, west London, at the age of three, even though the two girls spoke only English. They are now fluent. “I think it’s the best way to learn a language,” says Paula, “you learn in the context of play and friendship.”

Paula is a French-speaking Canadian, which means that her daughters are entitled to a place at the prestigious French Lycée in South Kensington, London, along with other nationals from Francophone countries around the world. British pupils are rarely eligible for the Lycée or for any of the other specialist schools for foreign expatriates. In fact, unless at least one parent is a native French speaker with an appropriate passport, most British families can forget this style of education.

The closest our state sector comes is Hockerill Anglo-European college (www.hockerill.herts.sch.uk) in Bishop’s Stortford, Hertfordshire, a state boarding school where many lessons are taught in French or German.

Some local authorities are already trying to make language learning a fixture in primary education. In Liverpool, 30 primary schools now teach a foreign language with the help of peripatetic teachers.

But Terry Lamb, past president of the Association for Language Learning, remains gloomy, despite the government’s latest proposals.

“Although there’s a lot of rhetoric, the bottom line is that language learning will be a matter of choice at primary school,” he says. “The strategy will change very little. It should be part of the national curriculum if they’re going to take it seriously.”