Walking into Donald Trump’s Oval Office is a test for any foreign leader. Last month, Germany’s chancellor, Friedrich Merz, aced it. “You speak such good English,” marvelled Trump. “Is it as good as your German, would you say?”

Merz, a senior counsel in international law firm Mayer Brown until 2021, is known for better English than his predecessors Angela Merkel and Olaf Scholz, and considers the language crucial for his government. He took office saying he would only nominate ministerial candidates from his party who spoke “English that is at least suitable for everyday use”.

Fluency in English — generally believed to be the most widely spoken language in history, with an estimated 1.5bn users worldwide (including 375mn native speakers) — has become a non-negotiable qualification for high-level jobs in many professions, sidelining people with a merely passable grasp of it. Its dominance is now being reinforced as AI shapes a new linguistic era. “An estimated 90 per cent of training data for current generative AI systems stems from English,” writes Celeste Rodriguez Louro of the University of Western Australia. As more jobs require working with AI, native anglophones will benefit.