The first international treaty written in English was the Treaty of Versailles in 1919, marking the end of the First World War.  Although most people probably believe English had been the international lingua franca for much longer than this – at least centuries – its global prominence has grown up over little more than a century, largely coinciding with the rise of the United States as a world power, rather than the British Empire as we might assume.

These days, English is spoken usefully by around a quarter of the world’s population – far more than even its nearest competitor. Although some think Mandarin is threatening to knock it from the top spot, it is already taught from primary level up in China; it is spoken by one in six Russians, and the working language of the European Union.  All pilots and airport control towers are required to speak it.  There are massive earnings to be made from teaching English as a foreign language (worth over £2 billion in the UK, and £3 billion by 2020).

So English looks safe for now as an international language of business, but it is not mere practicality that defines linguistic dominance – it has always been about prestige.  The tongues we use, whether Latin, Farsi, French or English, come from a need to impress, and in a world where 1.75 billion speak English, those who can communicate with a client in their own language hold a key advantage.

The eyes of the world have been turned for some years now not only on the US and UK, but on the emerging powers of Brazil, Russia, India, China and South Africa – the so-called ‘BRICS’ countries.  While some of these have historically spoken English as a language of the state, it’s likely that the influence of languages like Hindi and Afrikaans will rise to greater prominence alongside growing political (and military) power.  We don’t know which will come out on top, but we do know that future-proofing inevitably means investing in your linguistic arsenal.