In spoken and written language, in colloquial and formal context. Is there a general rule to use in sentences like the following:
"How many broken yellow plastic toys?"
"All those old yellowish lost scholar books."
In spoken and written language, in colloquial and formal context. Is there a general rule to use in sentences like the following:
"How many broken yellow plastic toys?"
"All those old yellowish lost scholar books."
The answer is seven. Seven adjectives.
You can have as many as you like, consistent with the patience of your readers or listeners.
No rules.
But I'd opine, FWIW, (not much), off the top of my head, that you'd get away with three on most occasions without it being too too obvious that you were pushing the limits, and that beyond that you'd probably want some special euphony or alliterative effect or other special-case reason, to make it seem other than just strained, "try-hard", or plain wrong.
A general rule for multiple adjectives modifying one noun in English orders the adjectives by their semantic category:
value > size > dimension > various physical properties > color
e.g., nice fat long crispy dark-brown pretzels.
See the citation in the first paragraph on p.2 of Kemmerer et al (2008) for more on this. My guess is that the major consideration in acceptability of multi-adjective noun phrases is that all of the adjectives refer to orthogonal characteristics of the object referred to. It would not do, for example, to have two different color adjectives.
As with any art form, the more skilled you are at writing, the more bizarre your writing can be. Kris's comment about 3 adjectives in a row is standard and I agree with it, but the first example, "broken yellow color toys", doesn't work for me, and the second, "old yellowish lost scholar books" is even less successful. Barrie's pragmatic approach seems sage advice. Another way of saying it is: However many you can get away with chaining together. Readers aren't very patient about that kind of thing if it happens often.