SOME seven centuries ago, it was the language of the underclass, the servants to their Norman masters. Not for nothing does it supply the words for most domestic animals - cow, calf, sheep, swine, deer - while words for the meat - beef, veal, mutton, pork, venison - come from the French.

But now, the language which Robert of Gloucester described as the tongue of the "low people" in the 13th century, is on the verge of global domination.

With around 340 million native speakers, English is already the fourth most commonly-spoken language, and by far the most widespread. It is the language of science, diplomacy, aviation and computing. Some 300 million people speak English as their second language, and another 100 million as a foreign language.

And its rise to ascendancy seems unstoppable. Yesterday, a report for the British Council predicted that by 2015, half the world's population will be speaking English, some three billion people, with around one billion of these native speakers.

But while this may be good news for the English, a nation renowned for a lack of ability at learning other languages, the prospect has not met a universal welcome. The rise of English can only be at the expense of other tongues, and as languages disappear so will cultures, replaced by a vast, globe-spanning, monolithic civilisation.

The historic domination of English can be traced to two factors: the British Empire and the cultural hegemony of the United States.

The creation of the largest empire the world has seen means English is spoken as a first language in all four corners of the world, from Australia to India, where it is an official tongue along with several Indian ones, and from South Africa to Canada.

And while English may be only the fourth most spoken language, it is the official or co-official language of more than 45 countries, compared with 27 for French, 20 for Spanish and 17 for Arabic.

It is this spread which helped English become a language of communication between nations, but it is the US which has made it truly pre-eminent.

England and America may be two countries divided by a common language, or so reckoned George Bernard Shaw, but the coincidence of the United States' military, economic and cultural supremacy with the advent of mass communication, has given English a global reach it could never have otherwise achieved.

Thus, the position of French as the international language of diplomacy was only challenged when US President Woodrow Wilson insisted that the 1919 Treaty of Versailles was also in English. By 1940, when Germany and Japan were negotiating their alliance against America and Britain, the two foreign ministers held their discussions in English.

Today, around 85 per cent of all international organisations use English as an official language. Around half of all business deals are conducted in English, and four fifths of scientific papers are published in English. Around 70 per cent of all mail is written and addressed in English.

But if Empire and the States can account of the rise of English, it is computing which is pushing it into hitherto unconquered realms. In the early days of mass computers, the French made a valiant attempt to assert their individuality with their own Minitel system, but that has long since vanished.

"Somehow, English got a grip of the web, and around 75 per cent of web pages around the world are in English," says Vivian Cook, professor of applied linguistics at Newcastle University and author of the spelling guide, Accommodating Broccoli at the Cemetery.

The stranglehold which some computing companies, particularly Microsoft, have exerted on the market has ensured English has become the first language of the web. Now, English is also the accepted language of email.

"There have been studies of Syrian businessmen who sent each other emails in English because it is easier than doing it in Arabic, and one of my students did a study of how Greeks sent emails: using the Greek alphabet is difficult on a computer, so they have a way of turning it into the Roman alphabet," says Prof Cook.

But the worry is that English will eventually squeeze out other languages. If languages are learned because they are needed, then the absence of need may see their extinction. Of the 6-7,000 languages in the world, around 100 disappear every year, and this trend can only increase.

Attempts to keep a language alive may see a temporary renaissance, witness the reinvigoration of Welsh with the help of television and government interference, but some experts predict that around half the world's languages will be gone by the end of the century.

'Languages come and go, they respond to the needs of people and they die out when there aren't people who need that language any more," says Prof Cook.

"But there is a tremendous amount of multilingualism - there are around 300 languages spoken in London - and people go to great lengths to keep their language alive. As well as the spread of the one dominant language in most countries, there are groups of speakers of other languages who survive."

He says one scenario is that English could go the way of Latin, which split into French, Spanish and Italian. As local dialects and phrases become more widespread, variations of English could turn into separate languages in their own right.

And if this does come to pass, then at the very moment of its triumph as the global first language, English could contain the seeds of its own decline. Just when a unifying tongue is nigh, a whole new family of languages could emerge.