(FORTUNE Magazine) – Didier Benchimol lives in Paris. He grew up in Paris. He went to college in Paris. He runs a company founded in Paris and based in Paris. But from the moment he gets to work in the morning till he goes home at night, he speaks nothing but English.

He speaks it well, with lots of American business jargon and only the charming residue of a French accent. But that's not good enough for him. He's been working with a speech coach to conquer that blandest and least identifiable brand of American English: Californian.

"I would like to really spend more time on this," Benchimol says of his language lessons. "Reaching the stage where people cannot differentiate where you are coming from is a sign that you are really global."

The 39-year-old Benchimol, CEO of an e-commerce software company called Imediation, is admittedly an extreme case. But he's not the only French executive speaking a lot of English these days. Turn on CNBC or CNN and you'll see the likes of Vivendi's Jean-Marie Messier or France Telecom's Michel Bon touting his company's prospects without an interpreter in sight. Look through the listings for professional and managerial jobs in French newspapers and recruitment Websites and you'll find that those that don't require anglais courant are few and far between. English is now the official language of the country's second-largest company, oil giant Totalfina Elf, and the de facto language of the largest, the financial conglomerate Axa.

That English use is on the rise around the world, especially in business circles, is nothing new. But this is France we're talking about, the headquarters of the global battle against American cultural hegemony. If these guys are giving in to English, something really big must be going on. And something big is going on.

Partly, it's that nasty American hegemony. Didier Benchimol feels compelled to speak English perfectly because the Internet software business is dominated by Americans. He, Jean-Marie Messier, Michel Bon, and their ilk also have to speak English because they want to get their message out to American investors, possessors of the world's deepest pockets. But this U.S. preeminence could be temporary. A decade and a half ago, you might recall, ambitious college kids the world over were studying Japanese in order to be able to do business with what was soon to be the world's foremost technological, financial, and economic power. Oops! (Or, if you went to the effort to learn Japanese: Otto!)

The triumph of English in France and elsewhere in Europe, however, may rest on something more enduring. As they become entwined with each other politically and economically, Europeans need a way to talk to one another and to the rest of the world. And for a number of reasons, they've decided upon English as their common tongue. "This may be a shame, but when I speak to an Italian guy, I speak in English," says Benchimol. "When I speak to a German guy, I speak English."

So when German chemical and pharmaceuticals company Hoechst merged with French competitor Rhone-Poulenc last year, the companies chose the vaguely Latinate Aventis as the new company name--and settled on English as the company's common language. When monetary policymakers from around Europe began meeting at the European Central Bank in Frankfurt last year to set interest rates for the new Euroland, they held their deliberations in English. Even the European Commission, with 11 official languages (for the record: Danish, Dutch, English, Finnish, French, German, Greek, Italian, Portuguese, Spanish, and Swedish) and a traditionally French-speaking bureaucracy, effectively switched over to English as its working language last year, with the ascension of Italian politician Romano Prodi to its top job.

How did this happen? One school attributes English's great success to the "sheer weight of its merit," as the American critic H.L. Mencken argued in 1935. It's a Germanic language, brought to Britain around the fifth century A.D. During the four centuries of French-speaking rule that followed the Norman Conquest of 1066, the language morphed into something else entirely. French words were added wholesale, and most of the complications of Germanic grammar (genders, cases, etc.) were shed while few of the complications of French were added. The result is a language with a huge vocabulary and a simple grammar that can express most things more efficiently than either of its parents. What's more, English has remained ungoverned and open to change--foreign words, coinages, and grammatical shifts--in a way that French, ruled by the purist Academie Francaise, has not.

So it's a swell language, especially for business. But the rise of English over the past few centuries clearly owes at least as much to history and economics as to the language's ability to economically express the concept win-win. What happened is that the competition--first Latin, then French, then, briefly, German--faded with the waning of the political, economic, and military fortunes of, respectively, the Catholic Church, France, and Germany. All along, English was increasing in importance: Britain was the birthplace of the Industrial Revolution, and London the world's most important financial center, which made English a key language for business. England's colonies around the world also made it the language with the most global reach. And as that former colony the U.S. rose to the status of the world's preeminent political, economic, military, and cultural power, English became the obvious second language to learn. Even before World War II it was pushing out German as the main foreign language taught in Northern Europe, and after the war linguistic victory was complete--notably in the Continent's two most populous countries, Germany and France. By the 1970s, English was replacing French in the schools of Southern Europe, and after the fall of the Soviet Union in the early 1990s, it took over from Russian in Eastern Europe. (There has also, of course, been the much condemned colonization of Europe by the American entertainment industry, but its linguistic impact has been limited chiefly to pop songs, as movies and TV shows are usually dubbed in local languages.)

So even in haughty, occasionally Anglophobic France, kids have been studying English in school for decades. Not always to great effect. "I was very good in translating Tennyson or Byron," recalls 58-year-old French businessman Jacques Machurot of his schoolboy English. "But I was not able to order a rare steak in a restaurant." For Machurot that changed when he got a job in the oil business with Elf and started coming into regular contact with English. (He now speaks it constantly; the outdoor-advertising company he runs was bought last year by U.S.-based Clear Channel.)

In the 1990s more and more Europeans similarly found themselves forced to use English. The last generation of business and government leaders who hadn't studied English in school was leaving the stage. The European Community was adding new members (and with them new languages like Finnish and Swedish, which nobody outside Finland or Sweden could seriously be expected to learn) and evolving from a paper-shuffling club into a serious regional government that would need a single common language if it were ever to get anything done. Meanwhile, economic barriers between European nations have been disappearing, meaning that more and more companies are beginning to look at the whole continent as their domestic market. Similarly, the European financial structure--which revolved around big banks and lots of government interference--has started to unravel, giving way to border-crossing English-speaking debt and equity markets. And then the Internet came along.

The Net had two big impacts. One was that it was an exciting, potentially lucrative new industry that had its roots in the U.S., so if you wanted to get in on it, you had to speak some English. (This had already happened with semiconductors and software, but their appeal was less universal.) The other was that by surfing the Web, Europeans who had previously encountered English only in school and in pop songs were now coming into contact with it daily. Now you get people like Michele Appendino, a 38-year-old Milan venture capitalist specializing in Internet companies. That he speaks English all day isn't much of a shock: "Obviously Internet investing is all in English," he says. Less expected have been the e-mail jokes that his 69-year-old father--who, his son thought, didn't speak any English--forwards him. They're all in English.

None of this means English has taken over European life. According to the European Union, 47% of Western Europeans (including the British and Irish) speak English well enough to carry on a conversation. That's a lot more than can speak German (32%) or French (28%), but it still means most Europeans don't speak the language. If you want to sell shampoo or cell phones, you have to do it in French or German or Spanish or Greek. Even the U.S. and British media companies that stand to benefit most from the spread of English have been hedging their bets--CNN broadcasts in Spanish; the Financial Times has recently launched a daily German-language edition.

But just look at who speaks English: 77% of Western European college students, 69% of managers, and 65% of those ages 15 to 24. In the secondary schools of the European Union's non-English-speaking countries, 91% of students study English. All of which means that the transition to English as the language of European business hasn't been all that traumatic (especially since even companies that switch to English aren't expecting every last factory worker to master the language), and it's only going to get easier in the future. One of the Continent's earliest adopters of English was Italian semiconductor maker SGS, which made the move back in 1980, when Motorola veteran Pasquale Pistorio took over as CEO. "It was clear the only way we could be successful was as a global company, not a national company," Pistorio says now. "And the only business language worldwide is English." In Italy in 1980, knowledge of English wasn't exactly universal, and in the early days SGS had to invest a lot in language lessons. Now the company is Italian-French giant ST Microelectronics, and Pistorio, who's still in charge, says language training is no longer a big issue.

Still, there's clearly a market for business-oriented English instruction. Providing it are established players like Berlitz, EF Education, and Sylvan Learning Systems' Wall Street Institute (which has plastered the Paris Metro with ads reading "Do you speak English? Yes, I speak English. Wall Street English"), plus two well-funded Internet startups, Englishtown and GlobalEnglish. GlobalEnglish has signed deals with Deutsche Telekom and Telecom Italia to provide English instruction to employees, and expects to reel in more such big fish soon. Japan's a big potential market, too, as several major companies, such as Matsushita Electric and Hitachi, have declared English proficiency an important factor in the careers of their managers.

All of which means that English's lead as the world's most spoken language is only going to widen. There are 322 million native English speakers, according to the Dallas-based Summer Institute of Linguistics, plus--if you take the middle range of the many guesstimates floating around--another billion or so who speak it with a reasonable degree of competency. Meanwhile, there are 885 million native speakers of Mandarin Chinese, and most likely not enough people who speak it as a second language to equal the estimated English total of 1.3 billion. More important than the numbers is where English is found. It's spoken all over the world; it's the global language of commerce and of science; it's disseminated constantly and instantaneously by radio, TV, and the Internet. No language has ever had this kind of reach, and never has there been so much communication between the different corners of the globe.

For the world as a whole, it's hard to see this rise of a common global language as anything but positive. For native English speakers, though, there are some concerns. So far the rise of English has provided wonderful opportunities for globetrotting American and British executives, teachers, Internet gurus, and journalists. But if Didier Benchimol is in fact the wave of the future and executives the world over will eventually all sound as if they grew up in California, one assumes that global demand for actual Californians--at least those who don't speak any language but English--will decrease. Habla espanol?

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