Quickly is an adverb describing how they are running.
The definition of an adverb is a part of speech that provides a greater description to a verb, adjective, another adverb, a phrase, a clause or a sentence.
Beautifully, quickly and happily are each an example of an adverb.
any of a class of words used generally to modify a verb, an adjective, another adverb, a phrase, or a clause, by expressing time, place, manner, degree, cause, etc.: English adverbs often end in -ly (Ex.: fast, carefully, then)
Origin of adverbMiddle English adverbe from Classical Latin adverbium from ad-, to + verbum, a word
- The part of speech that modifies a verb, an adjective, another adverb, or an entire clause or sentence.
- Any of the words belonging to this part of speech, such as so, very, and rapidly.
Origin of adverbMiddle English adverbe from Old French from Latin adverbium ( translation of Greek epirrhēma ) ad- in relation to ; see ad- . verbum word, verb ; see wer-5 in Indo-European roots.
- Adverbs comprise a fundamental category of words in most languages. In English, adverbs are typically formed from adjectives by appending -ly and are used to modify verbs, verb phrases, adjectives, other adverbs, and entire sentences, but not nouns or noun phrases.