The abstract noun form of the adjective 'useful' is usefulness.The word 'useful' is the adjective form of the abstract noun use.
The adjective form for the verb to use is the past participle, used (a used car).The adjective form for the noun use is useful(useful information).
The word "useful" is an adjective because it can describe/modify nouns.The part of speech that the word useful is, is an adjective.
Useful is not a noun or a verb, it is an adjective. Adjectives are descriptive words used to describe nouns. For example, if you say, "the useful dog," useful is the adjective modifying dog, the noun.
"Useful" is an adjective that describes something as being beneficial or serving a purpose. It is not typically used as a verb in standard English.
The abstract noun form of the adjective 'useful' is usefulness.The word 'useful' is the adjective form of the abstract noun use.
Quite is an adverb; useful is an adjective.
usefulness
No, it is not an adverb. Useful is an adjective and the adverb form is usefully.
There is no predicate adjective in that sentence. If it read, "Bird feeders are useful by providing us with yearlong enjoyment," "useful" would be a predicate adjective. In this case the simple predicate "are" connects the adjective "useful," included in the complete predicate, with the subject "bird feeders."
Used is a verb (past tense of use) and an adjective (a used car).
The word "useful" is an adjective in the phrase "quite useful" as it describes the noun it is modifying.