In what way is the negative form of a verb an adjective?

Question

I was reading the [wikipedia page on "predicate,"](http://en.wikipedia.org/wiki/Predicate_%28grammar%29) where it mentioned that in Japanese, the negative form of a verb is an adjective. I thought that this was too expansive a statement to be true, but what does the writer mean? Does the writer mean that only verbs in the ない form of the negative are adjectives? Is this still too broad in meaning to be true?

Answer 1

The ~ない form (non-past informal form of a verb) conjugates like an adjective and will work like an adjective in some cases. I'm not sure if you can call it an adjective, though.