Adverb

is /ad/ and /verb/. /ad/ means /addition/ or something to modify. Adverb then is to modify a verb.

For example:

The word /fast/ is the adverb (of manner). /fast/ modifies how he drives. Here, /fast/ refers to the verb /drives/. There are many kinds of adverbs in English. In this opportunity, we just classify the adverbs and discuss what the adverb is.

Types Of Adverbs

Adverb of Place

An adverb which shows where, e.g. here, there, to school, in the hospital, near the river, etc
For example:
Ann is in the hospital.

Adverb of Time

An adverb which shows when, e.g. now, yesterday, today, tomorrow, next month, before, since, etc
For example:
Tom is studying in the University of Leeds now.

Adverb of Quality

An adverb which shows quality, e.g. very. so, too, etc
For example:
I am very happy.

Adverb of Quantity

An adverb which shows how much or how many, e.g. any, much, some, several, etc.
For example:
I have some money in my pocket.

Adverb of Manner

An adverb which shows how or in what manner, e.g. fast, quickly, slowly, bravely, hard, soundly etc.

For example:
The children sings beautifully.

Adverb of Frequency

An adverb which shows how often e.g. always, often, seldom, sometimes, usually, etc.

For example:
My father always come in time.

Adverb of Affirmation and Negation

An adverb which shows stress and or negation, e.g. not, surely, certainly etc.

For example:
He certainly left.

Adverb of Reason

An adverb which shows Why, e.g. hence, therefore etc.

For example:
Today's raining. Therefore he stays at home.

Note: We'll discuss them in detailed later.

Irregular Adverbs

When there is Irregular adverb, there will be regular adverb. Irregular adverbs are adverbs which are derived from irregular adjectives, e.g. good, well, far, hard, fast, etc.

For example:

He speaks English well.

The word /well/ is in irregular adverb. It is derived from the adjective /well/. It is an adverb of manner. /well/  means /in a good manner/. So, when we would like to change the adjective /well/ into adverb of manner, we do not have to add the suffix /-ly/. On the other hand, /well/ is an adjective as well as an adverb of time.

Compare these following sentences:

I am well. (/well/=adjective)
He speaks English well. (/well/=adverb of manner).

Positions Of The Adverb

In sentences or in its usage, adverbs are usually positioned:
a. after Intransitive verbs,
e.g. He goes on time. (/on time/= adverb of time).

b. after Intransitive verbs, 
e.g. He goes there alone. (/there/= adverb of place).

c. after adverb of manner, 
e.g. He sings beautifully in the hall.

d. before verb, 
e.g. He usually goes home on time.

e. before an adjective or after the verb "be",
e.g. I'm never late to go to school.

f. before an auxiliary, 
e.g. I always have to go by bus.