An estimated 7,000 languages are being spoken around the world. But that number is expected to shrink rapidly in the coming decades. What is lost when a language dies?
In 1992 a prominent US linguist stunned the academic world by predicting that by the year 2100, 90% of the world's languages would have ceased to exist.
Far from inspiring the world to act, the issue is still on the margins, according to prominent French linguist Claude Hagege.
"Most people are not at all interested in the death of languages," he says. "If we are not cautious about the way English is progressing it may eventually kill most other languages."
According to Ethnologue, a US organisation that compiles a global database of languages, 473 languages are currently classified as endangered.
Among the ranks are the two known speakers of Lipan Apache alive in the US, four speakers of Totoro in Colombia and the single Bikya speaker in Cameroon.
"It is difficult to provide an accurate count," says Ethnologue editor Paul Lewis. "But we are at a tipping point. From here on we are going to increasingly see the number of languages going down."
What is lost?
As globalisation sweeps around the world, it is perhaps natural that small communities come out of their isolation and seek interaction with the wider world. The number of languages may be an unhappy casualty, but why fight the tide?
"What we lose is essentially an enormous cultural heritage, the way of expressing the relationship with nature, with the world, between themselves in the framework of their families, their kin people," says Mr Hagege.
"It's also the way they express their humour, their love, their life. It is a testimony of human communities which is extremely precious, because it expresses what other communities than ours in the modern industrialized world are able to express."
For linguists like Claude Hagege, languages are not simply a collection of words. They are living, breathing organisms holding the connections and associations that define a culture. When a language becomes extinct, the culture in which it lived is lost too.
The value of language as a cultural artefact is difficult to dispute, but is it actually realistic to ask small communities to retain their culture?
One linguist, Professor Salikoko Mufwene, of the University of Chicago, has argued that the social and economic conditions among some groups of speakers "have changed to points of no return".
As cultures evolve, he argues, groups often naturally shift their language use. Asking them to hold onto languages they no longer want is more for the linguists' sake than for the communities themselves.
Ethnologue editor Paul Lewis, however, argues that the stakes are much higher. Because of the close links between language and identity, if people begin to think of their language as useless, they see their identity as such as well.
This leads to social disruption, depression, suicide and drug use, he says. And as parents no longer transmit language to their children, the connection between children and grandparents is broken and traditional values are lost.
"There is a social and cultural ache that remains, where people for generations realize they have lost something," he says.
What no-one disputes is that the demise of languages is not always the fault of worldwide languages like our own.
An increasing number of communities are giving up their language by their own choice, says Claude Hagege. Many believe that their languages have no future and that their children will not acquire a professional qualification if they teach them tribal languages.
"We can do nothing when the abandonment of a language corresponds to the will of a population," he says.
Perhaps all is not lost for those who want the smaller languages to survive. As the revival of Welsh in the UK and Maori in New Zealand suggest, a language can be brought back from the brink.
Hebrew, says Claude Hagege, was a dead language at the beginning of the 19th century. It existed as a scholarly written language, but there was no way to say "I love you" and "pass the salt" - the French linguists' criteria for detecting life.
But with the "strong will" of Israeli Jews, he says, the language was brought back into everyday use. Now it is undeniably a living breathing language once more.
Closer to home, Cornish intellectuals, inspired by the reintroduction of Hebrew, succeeded in bringing the seemingly dead Cornish language back into use in the 20th Century. In 2002 the government recognised it as a living minority language.
But for many dwindling languages on the periphery of global culture, supported by little but a few campaigning linguists, the size of the challenge can seem insurmountable.
"You've got smallest, weakest, least resourced communities trying to address the problem. And the larger communities are largely unaware of it," says Ethnologue editor Paul Lewis.
"We would spend an awful lot of money to preserve a very old building, because it is part of our heritage. These languages and cultures are equally part of our heritage and merit preservation."