A lingua franca, according to the American Heritage Dictionary, is a "language used as a medium of communication between peoples of different languages." English has become the world's lingua franca---the most widely spoken in human history. But its dominance has so far lasted no more than two centuries---far shorter than the currency of many others, such as Greek, Latin, Malay, Swahili, or Persian. And now, as historian and linguist Nicholas Ostler persuasively argues in his provocative new book, English stands to be displaced as the world's language.The primary cause for the spread of lingua francas over time have been military empire-building, networks of commercial enterprise, and missionary religions. Ostler explores each of these inspirations through the lens of civilizations spanning the globe, from China and India to Persia, Africa, and Europe. Two long-term trends emerge that suggest the reasons for ultimate decline: Elites are the prime users of lingua francas, yet democratization in politics and rising equality in society tend to bring them down. Moreover, it is the prestige of dominance that sustains one lingua france over another; when the pecking order changes, so, sooner or later, will the choice of language. At present, international English worldwide is spoken not by majorities, but by elites; and the countries where English is spoken natively are losing their command of the world's economic heights. Soon, the rising wealth of states such as Brazil, Russia, India, and China will shrink any international preference for English.These trends are now reinforced by a new development in modern technology. There will soon be instant translation among major languages, enhancing the global usefulness of mother tongues and lessening the necessity for any future lingua franca to be learned. Increasingly, each nation will speak as it pleases, and yet the world will understand."A lingua franca is a language of convenience," writes Ostler. "When it ceases to be convenient---however widespread it has been---it will be dropped, without ceremony, and with little emotion." He predicts a soft landing for English: It will still be widely spoken, in its vast home territories, if no longer worldwide. But the decline of English will be symbolic and significant, evidence of grand shifts in the cultural effects of empire. The Last Lingua Franca is both an insightful examination of the trajectory of our own mother tongue and a fascinating view of the sweep of history. Read Less