Divisions of Grammar Definitions - Etymology.
An adverb is a word which modifies a verb, an adjective or another
adverb. Thus, in the example--"He writes well," the adverb shows the
manner in which the writing is performed; in the examples--"He is
remarkably diligent" and "He works very faithfully," the adverbs modify
the adjective diligent and the other adverb faithfully by expressing
the degree of diligence and faithfulness.
Adverbs are chiefly used to express in one word what would otherwise
require two or more words; thus, There signifies in that place;
whence, from what place; usefully, in a useful manner.
Adverbs, like adjectives, are sometimes varied in their terminations to
express comparison and different degrees of quality.
Some adverbs form the comparative and superlative by adding er and
est; as, soon, sooner, soonest.
Adverbs which end in ly are compared by prefixing more and most;
as, nobly, more nobly, most nobly.
A few adverbs are irregular in the formation of the comparative and
superlative; as, well, better, best.