I was asked by a student whether or not 'the described problem' was correct or not. Is it? It sounds really awkward to me and I would intuitively say 'the problem described'.
I have investigated of course and this is my solution to the problem:
'described' is not a real adjective, but a participle adjective, so it belongs BEHIND THE NOUN. Participle adjectives derive from a verb.
Let's make an example. A real adjective like 'beautiful' is used before the noun.
A beautiful woman talks to me - yay!
However, participle adjectives are a little different. They originate from a verb (e.g. ' to toss') and are put BEHIND THE NOUN.
I toss a stone. It hits a man in the face. (verb)
The stone tossed hits a man in the face. ('tossed' is a participle adjective)
If this is in any way wrong, please correct me. If not - use it