INTENSIFYING THE ADVERBIAL MEANING
As with adjectives, intensification may be (a) high, or (b) medium.

We saw that coordinated comparative adjectives indicate a progressively higher degree of the quality expressed: it’s getting colder and colder. Adverbial heads also participate in this structure, with the adverb as head or as modifier:
He drove faster and faster along the motorway.
Her paintings are selling more and more successfully every day.
Reduplicative adverbs have an intensifying effect:
very very fast much much better never ever through and through
over and over up and up again and again round and round
Attenuation
a bit harshly kind of hesitantly almost never
somewhat casually sort of sarcastically hardly ever
Quantification
As with adjectives, this refers mainly to circumstantial adverbs of space and time and may be either exact, or non-measurable:
Exact: Our houses are only two streets apart.
I saw her a moment ago.
Non-measurable: quantity is expressed by modifiers such as: soon after,
long before, quite near, shortly afterwards.
These circumstantial adverbs can be questioned by how + adj/adv:
How long have you been waiting? Not long.
How far is it to the railway station? Not far.
The focusing modifier: only
Only is a restrictive focusing adverb which can modify different units:
I wanted only one piece of toast.
We go there only once a year.
There is a tendency in spoken English to front the adverb to a position before the verb:
I only wanted one piece of toast.
We only go there once a year.
Describing and reinforcing
Adverbs of space or time are often preceded by other adverbs of space or time which reinforce or describe them more explicitly:
straight ahead back home up above early today
out there late yesterday down below out here
As with adjectives, we may note the emotive modification of adverbs by swear words such as damn(ed), as in You behaved damn foolishly, and other less polite ones.
Though less common in adverbial groups than in adjectival groups, modifiers can be found sub-modified, or even sub-sub-modified, especially in spoken English:
rather less fluently
very much more profitably