No. It may be a pronoun, adjective, or conjunction.
both is so an adverb!
Isn't is a contraction of both a verb and an adverb. Is (verb) not (adverb).
the word" comfortable " can be used both ways as an adverb or adjective.
both
The adverb in your sentence is 'thereafter'.
Yes the word "early" can be both an adjective and an adverb.
Not both together. Go is a verb, and back is the adverb.
It can be, because slow is both an adjective and adverb. But the comparative form of the adverb could also be "more slowly."
Its both
Both!
both
Both!