Staying with the exchange partners' families, they have been soaking up London's youth culture as well as dipping deeply into two of the ethnic communities in the capital. It has been "really good for them in so many ways," says their teacher Claire Zepilli.
For the third week, the students separate and go to jobs, matched as far as possible to their aspirations: helping in the Jewish primary school, an Italian book shop, the Jewish museum.
For the final week of their stay, the English and French students collaborate on producing a display of impressions. Romain and Cecilia are shooting a video. Others will make posters, diaries, pamphlets.
The material will be stored. Then, when the three-year project has finished, students' impressions of six ethnic communities in London and six in Paris will be put together in an exhibition.
The Parisians and their 12 English opposite numbers visiting Paris are in the vanguard of a European initiative to bring people closer together. Dialogue 2000 offered up to #163;11,000 a year per country for educational and cultural exchanges over three years. There are 25 projects in the scheme.
It was "too good to miss", says Ben Taubman, senior teacher at Christ's College, Barnet, north London. Christ's College already had French exchange partners for its International Award programme (TES, September 12,1997).
It was relatively simple to "rush over to Paris" and, with Mme Zepilli from Lyc#233;e Paul Langevin in Suresnes and Dominique Chiaramonti from #201;variste Galois in Sartrouville, expand their continuing programme of two-week work and education exchanges to four-week stints focusing on cultural diversity.The theme, echoing the colonial pasts of both countries, was an inspired collaboration; the planning was good-humoured hard work.
The hard part has been co-ordinating the funds and the bureaucracy. Mme Zepilli shakes her head sadly. "It is so terribly slow, the bureaucracy. We have students who have had to ask the school for the money."
Dialogue 2000 has been prompt with the funds in the UK, but the teachers on both sides had to organise supply teachers, travel tickets, allowances, some accommodation, admission charges to museums, a reception in the House of Commons, art and teaching materials for the exhibition, and production of a handbook has been "a headache", says Mr Taubman.
In a typical lesson at Christ's College, #201;milie, 17, asks: "Deepash, what is that colour in your hair - not blue, not green?" nudging Cecilia, 16, but unable to remember the English word "turquoise". Cecilia looks at Deepash: "Non, c'est vert!" Subdued giggles round the table as the students settle down for their Gujerati lesson among their English peers.
Teacher Anju Shah beams as she holds up a tomato. "Deepash, I think you know what this is in Gujerati? Tell us." No giggles now but furious concentration on new vocabulary and pronunciation. You can feel the pupils avidly soaking up new experiences.
Mrs Shah is pleased. "If all students were so quick as you I would be out of a job. We shall go shopping in Wembley on Saturday and you can try to buy this in Gujerati."
One rainy winter morning at the Hindu temple in Neasden, north London, the French party is gliding with "oohs" and "aahs" through the spacious halls. They listen to the guide and ask about the construction of the building, fitted together like a jigsaw over three years, every piece hand-carved in India. They sit quietly in the temple and puzzle animatedly over the display in the museum. Cecilia exclaims about the temple's impact: "So white in the middle of these poor red houses, red like everything in England."
Only the food in the cafe-teria gives them concern. It is so hot, if you are not used to it, says Romain ruefully. The food, they agree, has been their biggest shock. Not only does it taste different, it is served differently and has different rules attached. Cecilia says: "They never have dinner together. The mother comes too late. You just take your plate and go to the TV." So what
does Cecilia, from the land of the gourmet, think of the TV dinner? "I think it is good. You have your freedom. You eat what you like. It is good."
milie agrees. She likes the freedom, too. "We go out, my partner takes me everywhere." But Romain is not so sure. "It really is more free, in dressing, thinking, you can do what you want, you can go on a lot of outings. But I don't know if I would work if I lived like this."
Deepash grins uncomfortably. They have spent a lot of time going to Camden Lock, famed among French teenagers for its trendiness. That's where the hair assumed its turquoise hue. Here is a real culture clash. In Paris the students don't go out in the week. They must eat at the family table. They must dress according to a code. Ben Taubman is unsure how his trendy north London boys will take to bourgeois French suburbia. "We have to make sure they can meet up with each other. We are tapping into the unknown here."
But Chris, 17, has another view. "I like having my exchange partner. He is serious and does not want to go out all the time, he likes to work. It's good for me." As well as exploring different groups in the city, then,the students have been exploring the experiences of their peer group. "It's amazing how it has changed them already," says Claire Zepilli. "Some of them were worried that they were staying in an Indian family. But now they talk about how getting to know people is the only answer. The Dialogue 2000 people are right. Soon you won't be able to breed prejudice in these students. "