An adverb is a word or an expression that generally modifies a verb, adjective, another adverb, determiner, clause, preposition, or sentence. Adverbs typically express manner, place, time, frequency, degree, level of certainty, etc., answering questions such as how, in what way, when, where, to what extent. This is called the adverbial function and may be performed by single words (adverbs) or by multi-word adverbial phrases and adverbial clauses. Adverbs are traditionally regarded as one of the parts of speech. Modern linguists note that the term "adverb" has come to be used as a kind of "catch-all" category, used to classify words with various types of syntactic behavior, not necessarily having much in common except that they do not fit into any of the other available categories (noun, adjective, preposition, etc.) Functions The English word adverb derives (through French) from Latin adverbium, from ad- ("to"), verbum ("word", "verb"), and the nominal suffix -ium. The term implies that the principal function of adverbs is to act as modifiers of verbs or verb phrases. An adverb used in this way may provide information about the manner, place, time, frequency, certainty, or other circumstances of the activity denoted by the verb or verb phrase. Some examples: She sang loudly (loudly modifies the verb sang, indicating the manner of singing) We left it here (here modifies the verb phrase left it, indicating place) I worked yesterday (yesterday modifies the verb worked, indicating time) You often make mistakes (often modifies the verb phrase make mistakes, indicating frequency) He undoubtedly did it (undoubtedly modifies the verb phrase did it, indicating certainty) Adverbs can also be used as modifiers of adjectives, and of other adverbs, often to indicate degree. Examples: You are quite right (the adverb quite modifies the adjective right) She sang very loudly (the adverb very modifies another adverb – loudly) They can also modify determiners, prepositional phrases, or whole clauses or sentences, as in the following examples: I bought practically the only fruit (practically modifies the determiner the in the noun phrase, "the only fruit" wherein "only" is an adjective) She drove us almost to the station (almost modifies the prepositional phrase to the station) Certainly we need to act (certainly modifies the sentence as a whole) Adverbs thus perform a wide range of modifying functions. The major exception is the function of modifier of nouns, which is performed instead by adjectives (compare she sang