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 theadverbial function, and is realized not just by single words (i.e., adverbs) but by adverbial phrases and adverbial clauses.

The part of speech (or word class) that is primarily used to modify averb, adjective, or other adverb. Adverbs can also modifyprepositional phrases, subordinate clauses, and completesentences. Adjective: adverbial.

An adverb that modifies an adjective ("quite sad") or another adverb ("very carelessly") appears immediately in front of the word it modifies. An adverb that modifies a verb is generally more flexible: it may appear before or after the verb it modifies ("softly sang" or "sang softly"), or it may appear at the beginning of the sentence ("Softly she sang to the baby"). The position of the adverb may have an effect on the meaning of the sentence.
Functions of an Adverb:
Adverbs typically add information about time (rarely, frequently, tomorrow), manner (slowly, quickly, willingly), or place (here, there, everywhere) in addition to a wide range of other meanings.
Forms of an Adverb:
Many adverbs--especially adverbs of manner--are formed from adjectives by the addition of the ending-ly (easily, dependably). But many common adverbs (just, still, almost, not) do not end in -ly, and not all words that end in -ly (friendly, neighborly) are adverbs. See "Observations," below.

Types of Adverb Adverb modifies verb by giving us the following information. 1. How the action occurs 2. Where the action occurs 3. How many times action occur 4. At which time the action occurs 5. Intensity of action Adverbs are categorized on the basis of it information it gives, into the following categories. 1. Adverbs of manner 2. Adverb of place 3. Adverb of time 4. Adverb of frequency
Adverbs of Manner
These adverbs tell us that in which manner the action occurs or how the action occurs or occurred or will occur.
Examples.
She speaks loudly. He was driving slowly. You replied correctly. He runs fast. They solved the problem easily. Listen to me carefully. Adverb of Place.
Adverb of place tells us about the place of action or where action occurs/occurred/will occur.
e.g. here, there, near, somewhere, outside, ahead, on the top, at some place.
Examples.
He will come here. The children are playing outside. He was standing near the wall. They were flying kites on the top of hill. He lives somewhere in New York. She went upstairs.
Adverb of time
These adverbs tell us about the time of action. e.g. now, then, soon, tomorrow, yesterday, today, tonight, again, early, yesterday.
Examples.
I will buy a computer tomorrow. The guest came yesterday. Do it now. She is still waiting for her brother. He got up early in the morning. Adverb of frequency
Adverbs of frequency tell us how many times the action occurs or occurred or will occur.
e.g. daily, sometimes, often, seldom, usually, frequently, always, ever, generally, rarely, monthly, yearly.
Examples.
He goes to school daily. She never smokes. He is always late for class. They always come in time. Barking dogs seldom bite. The employees are paid monthly. The employees are paid every month. Adverbs of Time
These adverbs answer the question ‘when’. Examples are: tomorrow, today, yesterday, now, then, never, soon, already, ago, formerly, lately etc.
We are late.
She died two years ago.
I wrote to him yesterday.
Have you seen him before?
May I leave now?
I will soon return.
He will come tomorrow.
I have warned him already.
I haven’t read anything lately.
Adverbs of Place
These adverbs answer the question ‘where’.
Examples are: here, there, upstairs, downstairs, everywhere, nowhere, in, out, inside, away.
We have been living here for several years.
I searched for him everywhere.
They went upstairs.
May I come in?
She came forward.
I decided to go there.
Adverbs of Frequency
These adverbs answer the question ‘how often’. Examples are: again, frequently, always, seldom, hardly, often, once etc.
You are always welcome.
I have gone there only once.
We visit them frequently.
I often go there.
Adverbs of Number
These adverbs answer the question ‘in what order’.
Examples are: firstly, secondly, lastly, once, never, twice etc.
I have seen him only once.
Secondly, I can’t afford to buy it.
Adverbs of Manner
These adverbs answer the question ‘in what manner’. Examples are: slowly, carefully, terribly, seriously, well, pleasantly, really, thus etc.
The soldiers fought bravely.
Walk carefully.
I was terribly upset.
He is seriously ill.
She was pleasantly surprised.
She can speak English well.
Adverbs of Degree or Quantity
These adverbs answer the question ‘how much’ or ‘in what degree’.
Examples are: much, very, fully, partly, little, enough, so, rather etc.
He is quite strong.
She is very beautiful.
I am fully prepared.
My work is almost finished.
This is good enough.
You are absolutely right.
He is entirely wrong.
He was rather busy.
Adverbs of reason
These adverbs answer the question ‘why’.
Examples are: therefore, hence, thus, consequently etc.
He did not work hard, therefore, he failed.
Consequently he refused to come.
Adverbs of Affirmation or Negation
Examples are: surely, yes, no, certainly etc.
I will not come.
We will certainly help you.
Note that when used alone yes or no represents a whole sentence.
Will you come? Yes. (= Yes, I will come.)
Have you finished the work? No. (= No, I haven’t finished the work.)