Given that a staggering 1,500 languages could vanish by the end of this century, by some estimates – close to a quarter of the world’s total – some may find it obscene to even ask this question. English is certainly not on the endangered list. As the one truly global language, it is more often labelled an exterminator, a great lumbering titanosaur that unwittingly crushes hapless smaller languages underfoot – or undertongue. The fact is, though, that no language has yet proved eternal. Subjects of the Roman or Egyptian empires might once have assumed that their languages would last for…