system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does English invariably demand that multiple adjectives precede its noun in the seemingly arbitrary but non-negotiable order of 'opinion - size - shape - colour - origin - material - purpose'?

You can have a 'lovely little old rectangular green French silver whittling knife', but mess with this word order in the slightest and you'll sound like a proper maniac.
gpt
Well, first off, you're missing four in your description and your example is out of order. And if your example sounds good to you, ask yourself if you're a proper maniac (you're not).

You're missing; quantity, which comes first; physical quality, which comes after size but before shape; age, which comes after shape but before color (your examples screws this up); and type, which comes after material and before purpose.

Some lists will have them in different orders, this one is from Cambridge University. And the fact of the matter is that it doesn't actually matter that much, it isn't actually a hard-and-fast rule.

The list keeps getting longer, too. At one point it was just two things; opinion and then fact. Then it was opinion > fact; qualifier > function. Now it's opinion > fact, qualifier > function, but only for correlatives (adjectives that modify nouns without modifying each other). Operators and cumulative words don't follow this trend.

As for why... well, it's a new area of study and no one's really figured that part out yet. We're still studying trends and old texts to see if they follow the example (and they don't, for sure) and even looking at different regions to see if we all do it the same (we don't).