Adverbs: A little step to show your existence.

An adverb is a word that changes or qualifies the meaning of a verb, adjective, other adverb, clause, sentence or any other word or phrase, except that it does not include the adjectives and determiners that directly modify nouns. Adverbs are traditionally regarded as one of the parts of speech, although the wide variety of the functions performed by words classed as adverbs means that it is hard to treat them as a single uniform category.
Adverbs typically answer questions such as how?, in what way?, when?, where?, and to what extent?. This function is called the adverbial function, and is realized not just by single words (i.e., adverbs) but by adverbial phrases and adverbial clauses.

Uses of adverbs

Adverbs are words like slowly, yesterday, now, soon, and suddenly. An adverb usually modifies a verb or a verb phrase. It provides information about the manner, place, time, frequency, certainty, or other circumstances of the activity denoted by the verb or verb phrase.
Examples:
1. She walked slowly. (Here the adverb slowly shows the manner in which she walked.)
2. The kids are playing together. (Here the adverb together provides information about how the kids are playing.)

Adverbs can also modify adjectives and other adverbs.
1. You are quite right. (Here the adverb quite modifies the adjective right.)
2. She spoke quite loudly. (Here the adverb quite modifies another adverb – loudly.)
In English, adverbs of manner (answering the question how?) are often formed by adding -ly to adjectives. Other languages often have similar methods for deriving adverbs from adjectives (French, for example, uses the suffix -ment), or else use the same form for both adjectives and adverbs. Some examples are listed under Adverbs in specific languages below.
Where the meaning permits, adverbs may undergo comparison, taking comparative and superlative forms. In English this is usually done by adding more and most before the adverb (more slowly, most slowly), although there are a few adverbs that take inflected forms, such as well, for which better and best are used.

Adverbs as a "catch-all" category

Adverbs are considered a part of speech in traditional English grammar and are still included as a part of speech in grammar taught in schools and used in dictionaries. However, modern grammarians recognize that words traditionally grouped together as adverbs serve a number of different functions. Some would go so far as to call adverbs a "catch-all" category that includes all words that do not belong to one of the other parts of speech.
A more logical approach to dividing words into classes relies on recognizing which words can be used in a certain context. For example, a noun is a word that can be inserted in the following template to form a grammatical sentence:

The _____ is red. (For example, "The hat is red".)

When this approach is taken, it is seen that adverbs fall into a number of different categories. For example, some adverbs can be used to modify an entire sentence, whereas others cannot. Even when a sentential adverb has other functions, the meaning is often not the same. For example, in the sentences She gave birth naturally and Naturally, she gave birth, the word naturally has different meanings. Naturally as a sentential adverb means something like "of course" and as a verb-modifying adverb means "in a natural manner". This "naturally" distinction demonstrates that the class of sentential adverbs is a closed class (there is resistance to adding new words to the class), whereas the class of adverbs that modify verbs isn't.
Words like very and particularly afford another useful example. We can say Perry is very fast, but not Perry very won the race. These words can modify adjectives but not verbs. On the other hand, there are words like here and there that cannot modify adjectives. We can say The sock looks good there but not It is a there beautiful sock. The fact that many adverbs can be used in more than one of these functions can confuse this issue, and it may seem like splitting hairs to say that a single adverb is really two or more words that serve different functions. However, this distinction can be useful, especially considering adverbs like naturally that have different meanings in their different functions. Huddleston distinguishes between a word and a lexicon-grammatical-word.
Not is an interesting case. Grammarians have a difficult time categorizing it, and it probably belongs in its own class.

Prepositional adverb

A prepositional adverb is a word - mainly a particle - which is very similar in its form to a preposition but functions as an adverb. Prepositional adverbs occur mainly in English, German and Dutch. Unlike real prepositions, they occur mainly at the end of a phrase and not before nouns. They also modify the verb, which a preposition does not.
An example of a prepositional adverb in English is inside in He came inside.

Phrasal verb

A verb combined with a prepositional adverb is called a phrasal verb only if the verb's meaning is changed by the prepositional adverb. In English, there are lots of examples of this. For example, let can have many possible meanings depending on which prepositional adverb it is combined with (let down, let in, let off, let to etc.)

Pronominal adverb

A pronominal adverb is a type of adverb occurring in a number of Germanic languages, formed in replacement of a preposition and a pronoun by turning the latter into a locative adverb and the former into a prepositional adverb and joining them in reverse order.
For example:

• For that → therefor
• In that → therein
• By this → hereby
• To this → hereto
• In which → wherein

Usage in English

In English, pronominal adverbs are most commonly encountered in literary registers or in legal usage. They are used frequently by lawyers and drafters of legal documents primarily as a way of avoiding the repetition of names of things in the document (or sometimes as a self-reference to the document itself). For this reason, pronominal adverbs are often seen as a type of legal jargon.

Source: Wikipedia