An ELT Glossary : Adverb
"Adverb" is a difficult word class to define, as it contains a number of items which differ from each other in various ways. As Quirk et al (1972:267) say"...it is tempting to say simply that the adverb is an item that does not fit the definitions for other parts of speech."
Richards, Platt & Weber (1985:6) describe it as "a word that describes or adds to the meaning of a verb, an adjective, another adverb or a sentence, and which answers such questions as how? where? or when?" Some examples :
Modifying a verb : He spoke slowly.
Modifying an adjective : I was really tired,
Modifying another adverb : He spoke really slowly.
Modifying a sentence : Frankly, I expected him to fail.
There are therefore many different types of adverb, usually described with reference to their meaning. To give just a few examples:
Adverbs of manner (many of which end in -ly, some in - wise, others which have no morphological indicator) : slowly, clockwise, fast etc
Adverbs of place : here, there, locally etc
Adverbs of frequency : often, sometimes, never etc
Adverbs of time : today, then, now etc
Intensifying adverbs : really, quite, incredibly etc
Sentence adverbs, Frankly, Hopedfully, Interestingly, Luckily, etc
However, adverbs also divide into syntactic groups and may be adjuncts, disjuncts or conjuncts.
See also adverbial, adverb particle, adverbial clause.
Quirk, R. et al (1972) A Grammar of Contemporary English, Longman
Richards, J., Platt, J., Weber, H. (1985), Longman Dictionary of Applied Linguistics, Longman