Adverb

A verb, adjective, determiner, clause, preposition, or sentence is modified by an Adverb. Adverbs are used to express things like manner, place, time, frequency, degree, level of certainty, and so on. The term "adverb" has come to be used as a kind of "catch-all" category for classifying words with different types of syntactic behavior.

Adverbs of manner (answering the question how?) are frequently formed in English by adding -ly to adjectives (accidentally, angrily, automatically). Many other adverbs are not related to adjectives in this way; they could be derived from other words or phrases, or they could be single morphemes, here's a few examples how "adverbs" were used in sentences:

We left our bags there ("there" modifies the word "left", which indicates "place") I did my homework yesterday ("yesterday" modifies the word "did", which indicates "time") She often talks to my friends ("often" modifies the word "talk", which indicates "frequency") I certainly win ("certainly" modifies the verb "win", indicating certainty)