When J. R. R. Tolkien was about seven he wrote a story about a dragon. Years later he remembered only one thing about it, and he put it in a letter to W. H. Auden in 1955: his mother said nothing about the dragon, but pointed out that you couldn’t write “a green great dragon”. It had to be “a great green dragon”. He wondered why, he wrote, and still did. He was a professor of English by then.

Grammar books now give a rough answer, an order that runs opinion, size, age, shape, colour, origin, material, purpose. That is why you can own a lovely small old round blue Dutch china teapot, and why moving any one of those words makes it sound like a translation. Almost nobody who speaks English was ever taught the order. It sits underneath, like a floor nobody remembers laying, and you only find it when you put your foot through it, the way a seven-year-old does.

What I like is that naming the rule doesn’t explain it. Tolkien knew the history of English as well as anyone alive, and the honest thing he could say about that one sentence was that he still wondered.