Best Answer - Chosen by the AskerAdverbs are used to add information to three other types of words: verbs (think "ADD to the VERB = ADVERB"), adjectives, and other adverbs. The grammar language is that an adverb "modifies" (adds information to) these words.
An adverb modifying a verb:
"I learn foreign languages QUICKLY."
The word "quickly" tells more information about the verb "learn". Here it tells the rate of the learning.
An adverb modifying an adjective:
"I live in a RATHER large house."
The word "large" is an adjective, telling what kind of "house" (noun). The word "rather" adds information to the adjective "large" -- it tells TO WHAT DEGREE it is large.
An adverb modifying another adverb:
"I learn foreign languages RATHER quickly."
Here, the word "quickly" is still an adverb, as explained in the first example above. The word "rather" here tells more about the adverb "quickly" -- it tells HOW quickly.
Do remember that many parts of speech (e.g., noun, adjective, adverb, etc.) may be comprised of SEVERAL WORDS in a "phrase" (without a clear subject and verb within the group of words) or a "clause" (having a clear subject and verb within the group of words).
Ex: "I fell DOWN THE STAIRS."
Here, the subject of the sentence is "I" and the verb is "fell".
The word "down" is a preposition. The word "stairs" is a noun, which is the object of that preposition. (The word "the" is an article, which is a type of adjective.)
However, the entire prepositional PHRASE -- "down the stairs" -- is acting as an adverb, telling WHERE "fell" happened. This is a tricky point of grammar, but it is worth learning -- that adverbs can be words OR phrases OR clauses.