An adverb is a word that modifies or describes a verb, an adjective, another adverb, or even an entire sentence. Adverbs can be used to show manner (how something happens), degree (to what extent), place (where), and time (when) . They often end in -ly, but not always. Some common examples of adverbs include "really," "very," "well," "badly," "today," "yesterday," "sometimes," "often," "rarely," "early," "late," "here," and "there". Adverbs can also be used to modify entire sentences by expressing a viewpoint or making an evaluation, and these are called sentence adverbs. Some adverbs use the same form as their corresponding adjectives, and these are known as flat adverbs. Adverbs can provide context in a sentence by describing how, when, where, and to what extent something occurs.