Mark Abley speaks some languages that will be extinct before his book about them - encouraged by Nuala Ní Dhomhnaill - goes out of print, he tells Shane Hegarty.

There are about 6,000 languages in the world, and Mark Abley speaks a smattering of some that won't survive into the next generation. A Canadian, his English and French are fluent. The son of immigrants, he has passable Welsh. But as the writer of Spoken Here: Travels Among Threatened Languages he has collected the odd phrase in some languages that will be gone before his book about them goes out of print.

His is an erudite, entertaining and poignant journey through the intensive care ward of the world's tongues. Half our languages are not expected to survive this century. Ninety per cent are considered to be under long-term threat.

Abley's quest to learn more about this came about following an encounter with elderly Native Americans and was spurred on by an encounter with Irish poet Nuala Ní Dhomhnaill.

"It goes back to 1993 when I wrote an article on indigenous languages in Quebec," he explains. "One was extinct, another had only 10 speakers. I met the last speakers of this language and wrote of how sad it was that it would soon be gone. Yet it was inspiring too, because I found that there were women in their 80s who were still committed to not only speaking, but saving their language."

A few years later, he met Ní Dhomhnaill and realised that he needed to challenge his preconceptions about threatened languages. "That was something else which pushed me towards this book. I interviewed her for the Montreal Gazette and found that any sense I had of her being a traditionalist or looking backwards was completely dispelled. She was wonderful. She was passionate and fiery and if she chose to there was no doubt she could write just as well in English, but she chose to do so in Irish."

He is quick to point out that he is not a linguist, so the result is a book that is as interested in the speakers as in their languages. He meets Patrick, the last male native speaker of the Australian language Mati Ke. Yet tribal convention forbids him to talk to the last female speaker - his sister. There is also the story of a parrot who, once its owner died, became the last speaker of a South American language.

"I ran into a bit of trouble because of political correctness. This was interesting information, but there were some who thought I wasn't the person to write about it because my background is as an English-speaking Canadian. But I realised that I have a perfect right, because this is not a Canadian problem, it's a global one."

His Welsh roots proved an advantage. "When I was visiting indigenous communities, it helped if I could say that my parents were from Wales, so that I was not just this English-speaking guy. It gave me a minority language heritage and my own understanding of the problem."

While researching the topic, he travelled extensively: to Wales, the Isle of Man, the Faroe Islands, Australia and across the border to the US. He discovered that minority languages often struggle in similar conditions of poverty, oppression, shame and cultural disintegration.

Once the native language is perceived as a disadvantage by the 12-30 age group, he says, then it becomes a battle to save it - one that is sometimes lost before anyone realises it's started.

"Quite often they're not even aware of it vanishing within a community. Take the Mohawk language for example, where the elders are still speaking it, but it took them a while to realise that TV and radio were having such an impact that there's not much use in the younger people speaking it anymore. And in that community, it almost went too far to be able to bring it back. It was a real surprise to them."

He notes how English, especially, has crept into many languages by stealth, so that even strong languages such as Russian and German have stopped translating words; instead adopting the foreign word even when there is a colloquial alternative. In Germany, for instance, one travels to "die City for die Party". In Moscow, if you need cheering, someone might tell you: "Don't vori, bi khepi."

"It's not conscious," insists Abley. "English is the background noise of a lot of the planet. There are so many places where you will hear it spoken. Airports, universities and in large businesses. The presence of English is everywhere." It is becoming the global language, he says, in the way that those who invented Esperanto hoped their creation would be. In 1990, The Netherlands was within a whisker of abolishing Dutch as the language in schools, such was the global prevalence of English.

Yet, he found plenty of examples of resilience: the unique adaptability of various Creole languages; the way in which Hebrew returned as a spoken language after almost a century only as a ceremonial tongue; the resilience of Manx, which was pronounced dead in 1974, but has since enjoyed a comeback of sorts.

Such renaissance, though, needs consensus among speakers. "The example of Cornish is heartbreaking because they've been trying to bring it back for a couple of centuries now, but they can't agree on what exactly it is that they are trying to bring back. One thing I've learnt from this book is that there are no cultural group or peoples too small that there can't be infighting."

Unlike the environment, a language is a less tangible thing to save, so that for people on one side of the world, if a language spoken in some isolated peninsula thousands of miles away goes unnoticed, so does its extinction.

Abley acknowledges that he is not the first to equate the richness of languages with biodiversity. However, while he says the PR battle over threatened species was won a long time ago, he believes that the importance of language diversity is finally being recognised.

"We've all been aware of the statistics for some time, that 90 per cent of languages are under threat. But you can get stuck on it, and while many will die out I found more and more examples of resistance and some will fight back. The problems are still enormous, but I do think that the intellectual background climate is maybe changing.

"If I was writing the book again, I would emphasise the hopeful aspect a lot more."