Hacker News Reader

This is substantially true of English as well; we can construct a grammatically valid phrase such as "the sleepy gorillaesque lamppost".

With, of course, some exceptions. I'm confident there are exceptions in Japanese as well, being as exceptions are the rule in natural languages.

You can think of them as verb-like adjectives and noun-like adjectives, or you can think of them as adjective-like verbs and adjective-like nouns, but it really makes no difference one way or the other, and either way they are going to be their own separate categories.

... except for the fact that 形容詞 (i-adjectives) and 形容動詞 (na-adjectives) are used differently from 名詞 (nouns) and 動詞 (verbs). So there needs to be some distinction at some point, even if at the high level, 名詞 and 形容動詞 are similarish, and 形容詞 and 動詞 are similarish. But that doesn't go beyond -ish, and it's important to know.