Explain Adverbs Showing Degree or Extent

Using adverbs to show "how much"

Adverbs are modifiers. Most adverbs provide information about verbs. They indicate how, when, or where the verb happens.

However, adverbs can also modify adjectives and other adverbs. They describe to what degree or extent the adjective or adverb applies.

The most common adverbs that serve this function are so, very, really, quite, exceptionally, extremely, fairly.

Examples
1. We were quite exhausted after the lecture.

"Quite" indicates the degree to which we were exhausted. It modifies the predicate adjective "exhausted."

2. We left extremely quickly after class.

"Extremely" indicates how quickly we left. It modifies the adverb "quickly."