Advérbio

Adverb is the invariable word
That modifies the verb, an adjective or another adverb

Modifying the verb goes like this
The boy will sing
The boy will sing well

Modifying the adjective goes like this
The girl is happy
The girl is very happy

Modifying the adverb goes like this
They are all doing well
They are all doing very well

The adverb can be of place: Here, there, far, near
It can be of time: Early, late, tomorrow, later
It can be of manner: Like this, quickly, carelessly, aimlessly
It can be of negation: No, neither, never, never
It can be of doubt: Maybe, probably, perhaps
It can be of affirmation: Yes, certainly, for sure
It can be of intensity: Much, little, less, more
How much, almost, so much