No, it is acting as a noun.
Yes, it is an adverb. It means done each year.
The adverb is quickly.
No, it is a plural noun. The singular (year) can be a noun adjunct, and there is an adverb, yearly.
No, it is not an adverb. It is a negative verb form written as a conditional contraction. It means "could not" where not by itself would be an adverb.
The adverb of the sentence is quickly.
No it is a noun.
One adverb form of "imagine" is imaginatively. "His story was imaginatively written."
You could say 'he said sneeringly' which is an example of the adverb, but this is better written as 'he sneered'.
No. By itself, well can be an adverb. Written (here) is an adjective, as it is the past participle of to write.The term well-written should be hyphenated to form the compound adjective.
There are no adjectives or adverbs. The word 'a' is an article, not actually an adjective. The sentence "I have recently written a biographical book", for example, would have the adverb 'recently' (when was it written) and the adjective 'biographical' (what kind of book).
Yes. It is the adverb form of increasing (growing in number, value or size).
Yes. Unwillingly is an Adverb. Its antonym is a famous ballad written by Hank Cochran, "Willingly".