In England, English Muffins Are Just Called 'Muffins'
English muffins are an essential breakfast bread, and they serve as the foundation of what's arguably the finest brunch dish in the land: eggs Benedict. But even though the English muffin as we know it — specifically, the ones made by Thomas' — were introduced stateside by English émigré Samuel Bath Thomas in New York City in 1880, English muffins aren't actually an American invention, as some believe. They've been around in England since long before Thomas popularized them here. Go to any British supermarket, like Tesco or Sainsbury's, and you'll see them marketed as simply "muffins," or sometimes "breakfast muffins" or "toasting muffins."
Long before every British household had an oven of its own, what we call English muffins were usually sold door to door (hence the song "Do You Know the Muffin Man," which was being sung as early as 1820). These differed slightly from English crumpets, which are moister and chewier than English muffins due to the addition of (among other things) baking soda. After Thomas brought them to America, they quickly caught on at upscale hotels and restaurants as a fancier alternative to toast, and by the early 1900s they'd become commonplace.
But what about, you know, the sweet, cakey things that Americans call muffins? In the U.K., those are generally still just called muffins (because it's fairly easy to tell the two apart), but you'll sometimes see them referred to as "American muffins." English muffins definitely aren't a British food that Americans just don't understand.