The top 20 global languages - defined in terms of their use as a first or second language - provide an interesting reflection on the fortunes of those languages that have spread by organic growth and those that have expanded by means of mergers and acquisitions. At the top of the league table is Mandarin Chinese, which has 1,052 million speakers, more than twice as many as the next highest, English, with 508 million. Third is Hindi with 487 million and fourth Spanish, with 417 million. Of course, English is a far more global language - though primarily as a second language - than Chinese, the vast majority of whose speakers live in China. But with the present rise of China - and indeed India - it would not be difficult to imagine Mandarin and Hindi becoming far more widely spoken by 2100. By way of contrast, French, which until the early 20th century was, with English, the global language of choice, albeit with rather more prestige, now lingers in ninth place in the table, with a mere 128 million speakers - little more than half the number of Bengali speakers, and just above Urdu.
History teaches us that the future will always be shaped in large part by the unexpected and the unknowable: language is a classic case in point. Even the mightiest languages have fallen, and the future of the mightiest of our time - English - can never be secure or guaranteed, whatever the appearances to the contrary. Languages follow something like Darwin's law of evolution: they come and go, though their life spans vary enormously. Of the approximately 7,000 language communities in the world today, more than half have fewer than 5,000 speakers, and 1,000 fewer than a dozen: many will be extinct within a generation. But which languages, a millennium from now, will still be prospering, which will be the dominant global languages, and which will be the lingua franca? From our vantage point in the early 21st century, this remains entirely unpredictable.
From a review of Empires of the Word: A Language History of the World by Nicholas Ostler.