Believeran adjective in participle form
I can
see that you are a bit confused about the terminology. Adjectives
don't have "participle forms". You start with a participle, that
is, a verb form -- present participle or past participle of a
verb.
It may be part of a verb phrase, and often it is:
We are going to town tomorrow.
We have gone to Hawaii on vacation several times.
Or it may be used as an adjective, either a 'predicative' adjective (i.e., after a linking verb):
The child seemed very interested when the magician made the rabbit disappear.
or as an 'attributive' adjective (i.e., before the noun it modifies):
They decided not to disturb the sleeping dog.
or as an initial (adjectival) participial phrase, typically modifying the subject:
Frightened by the wolf, the bird flew into the nearest tree.
There are probably a few more patterns as well, but these are the most important.
In
some cases, grammarians don't even call verb forms like interested
(above) participles. They treat them as ordinary adjectives that
coincidentally resemble verb forms. Maybe that's the source of
your confusion. There are several different approaches to
participles, so it depends on which authors you read.
________
Believer the word 'powered' seems to be a participle acting as
an adjective.
Except when they are parts of verb phrases,
participles always function as adjectives, so yes,
powered is a participle and it is an adjective.
A fan-powered reprieve is a reprieve powered by fans (the people, not the machines, I suspect!)
The
same pattern cannot be applied at random, however, if that's what
you're asking. For example, you could not confidently use the
pattern a magician-interested child. (See my example above.)
CJ