While some argue that the infiltration of American English is constantly speeding up, Lynne Murphy, an American linguist living in the UK and a reader in linguistics at the University of Sussex, says that in fact the great era of American English as the language of the world was the 20th century, and it’s over.

“American culture (and words) could easily spread in the 20th century because it was hard to produce and distribute recorded entertainment, but the US had the capacity and the economy and the marketing savvy to do so,” Murphy wrote in a recent blog. What’s changed in the 21st century, she suggests, is that the internet has re-formed our relationship with media, making audiences less purely receptive, and more able to seek out the content that interests them. Ultimately, she argues, there’s more “exchange of words between people, rather than just reception of words from the media.”

“[P]opular songs are less universally popular, because people have more access to more different kinds of music on download,” she writes. “Instead of two or three or four choices on television, there are hundreds. And if you don’t like what you’re seeing you can go on YouTube or SoundCloud…and find all sorts of people doing all sorts of things.”

Geopolitics is also involved. During the last century, two world wars and the Cold War saw Americans posted all over the world, “using their slang in the presence of young recruits from other countries,” she writes. American manufactured goods were widely exported and advertised. With the election of Donald Trump as US president, however, the country’s rhetoric has become decidedly more isolationist. Murphy asks both whether its words and its culture will flow so freely abroad as before, and whether the rest of the world will be as receptive to them.

Not everyone agrees. Matthew Engel, author of forthcoming book That’s the Way it Crumbles—The Americanization of British English, argues that America’s cultural and technological strength globally make it hard for other languages—including French, German, and Italian as well as British English— not to metamorphose under its weight.