Usage of Adverbs

An Adverb always modifies the meaning of a Verb, an Adjective or even a Preposition.
Eg 1 : Don't speak loudly.  ('loudly' is an Adverb here which is modifying the verb speak)
Eg 2: Don't be so rash. ('rash" is an Adjective and so is modifying rash)
Thus 'the modifying words noted above' are the Adverbs.

Most adverbs end with "ly" but there are many adverbs which don't end with "ly". So observe the following examples.

A.  Adverbs of Manner :  Telling How or In what manner Eg: bravely, loudly, slowly, fast, entirely, very, too, much, Almost, nearly, quite, just, too, enough, hardly, scarcely, completely, very, extremely, rather
1. He fought bravely.
2. The boy laughs loudly.

B.  Adverbs of Place :  Adverbs of place tell us where something happens.  Eg: everywhere, behind, under, away, up, down, around, home, out, back, in, nearby, outside 
1. She was sitting here
2. My mother is out.

C.  Adverbs of Time :   Telling 'When'  Eg: daily, weekly, yearly, often, sometimes, rarely, seldom
1. He comes here daily
2. I saw her yesterday.

D.  Adverbs of Frequency:  Adverbs of Frequency are Adverbs of Time that answer the question "How frequently?" or "How often?". They tell us how often something happens.  Eg: daily, weekly, yearly, twice, thrice, often, sometimes, rarely, seldom
1. She takes the boat to the mainland every day.
2. She often goes by herself.

E.  Adverbs of Degree of Quantity:  Telling how much
1) I was very tired.
2) The mango is almost ripe.

F.  Adverbs of Reason :  He was therefore fined

G.  Affirmation or Negative :  
1. He did not come after all.
2. He is certainly alive.

I.  Interrogative Adverbs of Manner, Place, Time, Number, Quantity, Reason :  Where, When, How, Why, Therefore, How much , How far,

There are numerous adverbs but they should by properly used, but one should not be confused between the followings:

Rule 1: Hardly means almost none, and hard means heavily
Rama works hardly  
Rama works hard  
Rama hardly works  
Third sentence is correct as hardly indicates here, Rama is a lazy person.

Rule 2: Fast is an adverb.  Fastly has no meaning
 He walks fastly.  
 He walks fast  

Rule 3: Late means after the expected time.  Lately means recently.  
He came lately  
He came late.  
Have you seen her lately?  

Position of Adverbs: 

Rule 4: Adverbs of place, manner, time, generally put after the verb
We gave immediately our reply.  
We gave our reply immediately.  

The worker has satisfactorily done his work.  
The worker has done his work satisfactorily.  

Rule 5: Adverbs of frequency which answer the question "how often?" and certain other verbs like almost, already, hardly, nearly, just, quite are normally put between subject and verb. 
They come to see me seldom.  
They seldom come to see me.  

We try always to help him.  
We always try to help him.  

She feels sometimes resigning the job.  
She sometimes feels resigning the job.  

Gopal attended frequently the club meetings.  
Gopal frequently attended the club meetings.  

Nothing seems ever to change in this village.  
Nothing ever seems to change in this village.  

He is a careless fellow rather.  
He is rather a careless fellow.  

Rule 6: the adverb enough is always placed after the word which it modifies.
Her mother was enough foolish believe it.  
Her mother was foolish enough to believe it.  

The Indian army is enough strong to fight.  
The Indian army is strong enough to fight.  

Rule 7: 'Very' is used before the present participles and the Adverbs and Adjectives of the Positive degree and 'much' is used before the Adjectives and Adverbs of the Comparative degree 

I am much good now.  
I am much better now.  
He sang much sweetly.  
He sang much more sweetly.  
I am very amazed to find you here.  
I am much amazed to find you here.  
He arrived very sooner than expected  
He arrived much sooner than expected.  
He is very much late for the school.  
He is very late for the school.  
My brother is very much pleased with him.  
My brother is very pleased with him.  
He is much tired.  
He is very tired.  
She is very taller than her sister.  
She is much taller than her sister.  
His presence there was very much astonishing.  
His presence there was very astonishing.

Rule 8 : Too, Very:  "Too" indicates excess. It should not be used in the above sense.  It is better to use 'very'.
Geeta is too glad to meet you.  
Geeta is very glad to meet you.  
Sunil is too humble.  
Sunil is very humble.  
This manga is too delicious.
This mango is very delicious.  

You are very weak to walk.  
You are too weak to walk.  
Today's news is very good to be true.
Today's news is too good to be true.  

Rule 9 :  Ago  and Since
He visited Allahabad since three years.  
He visited Allahabad three years ago.  

Rule 10 :  After and since
Two years have passed after his mother expired.  
Two years have passed since his mother expired.  
She has been confined to bed from Tuesday last.  
She has been confined to bed since Tuesday last.