ADVERB

 An adverb is a part of speech. It is any word that modifies verbs or any part of speech other than a noun (modifiers of nouns are primarilyadjectives and determiners). Adverbs can modify verbs, adjectives (including numbers), clauses, sentences, and other adverbs.

Adverbs typically answer questions such as how?, in what way?, when?, where?, and to what extent?. This function is called the adverbialfunction, and is realized not just by single words (i.e., adverbs) but by adverbial phrases and adverbial clauses.

Adverbs are words like slowly, tomorrow, now, soon and suddenly. An adverb usually modifies a verb or a verb phrase. It provides information about the manner, place or circumstances of the activity denoted by the verb or verb phrase.

• She walked slowly. (Here the adverb slowly shows the manner in which she walked.)
• The kids are playing upstairs. (Here the adverb upstairs provides information about the place of the activity.)

Adverbs can also modify adjectives and other adverbs.

• You are quite right. (Here the adverb quite modifies the adjective right.)
• She spoke quite loudly. (Here the adverb quite modifies another adverb – loudly.)

Most adverbs are formed by adding –ly to adjectives. There are also adverbs that do not end with –ly. i. The athlete ran very fast so that he could set a new record. ii. Khalid worked hard to help his family. iii. The students came late for the seminar. iv. Mi sister performed well in the examination. There are many types if adverb. Examples are: adverbs of manner, adverbs of frequency, adverbs of time, adverbs of place, adverbs of certainty etc.

http://en.wikipedia.org/wiki/Adverb#Adverbs_in_English