An adverb is a word which modifies the meaning of a Verb, an Adjective or another Adverb.

Example :
The old man walked slowly .
Juli writes very carefully .
He works hard from dawn to night.

Type of Adverbs
Adverb of time
If a verb answers for question 'When' then the adverb shows the time of action.

Example :
He left the place a few minutes ago.
He will soon come back.

Adverb of Place
If a verb answers for question 'Where' then the adverb shows the place of action.

Example :
I met him in the Theatre.
This is the place where the tree stood.

Adverb of Number
If a verb answers for question 'How often' then the adverb shows the number of the action.

Example :
The comet appears once in several years.
That poor man is always happy
.

Adverb of Manner
If a verb answers for question 'How' or'In what manner' then it shows the condition of verb.

Example :
He was seriously injured.
Johny writes very carefully.

Adverb of Degree or Quantity
If a verb answers for question 'How much' or'In what' .

Example :
The sky is very cloudy.
She sings pretty well.

Adverb of Reason
If a verb explains the reason for the action then called adverb of reason.

Example :
As he was not well.
Therefore he returned home.