In Geneva, we started the new year with a conference organised by my school on "languages and education". Language teaching is a big issue in a country with four national languages, and in a city where more than 40 per cent of pupils are non-Swiss, and in a school like mine with 98 mother tongues among students.
We took as our motto Wittgenstein's statement that "the limits of my language are the limits of my world". Speaker after speaker showed the benefits of multilingualism and the limitations of monolingualism. Not only, we were told, is it possible for children of all abilities to acquire a second language with relative ease, but it can also be done so that it supports other parts of the curriculum and has no adverse effect on learning the first language. The key to success is the use of the second language to learn other subjects. It is helpful to start early, but intensive teaching later on is also perfectly possible and can produce striking results.
The evidence was backed up by the case of my own school. English-speaking students following our bilingual courses progress more rapidly in French when using it to learn history or maths than when simply studying it as a language. We are, of course, in a privileged position in Geneva, where pupils are surrounded by French and a knowledge of the language eases access to bars and discos and widens the pool of potential boyfriends and girlfriends. English students learning French in largely monolingual Manchester do not have the same advantages. But the basic principles - devoting a lot of time to the second language and using it in real situations - remain the same everywhere.
The conference reinforced my scepticism about the traditional model of learning another language, whereby one finds a small slot for it on the timetable and then gradually erodes it under pressure from other subjects.
Tinkering with this model is just fiddling at the margins. It is a reasonable model for raising awareness of linguistic and cultural diversity and encouraging a tiny minority to continue studying languages in later years, but it involves a massive disproportion between investment and outcomes that often result in little more than being able, while on holiday, to utter a few words to foreigners who then reply in fluent English.
It is time to look at radically different models that involve some degree of in-school immersion in a language, followed by carefully planned reinforcement. The logistical problems of teacher supply and mobility are huge, but anything else will be whistling in the wind.
Nicholas Tate is director-general of the International School of Geneva, Switzerland