What kind of adverb is used to modify an adjective?

Adverbs of degree modify adjectives to indicate a greater or lesser extent or characteristic.

Adverbs of frequency and time modify adjectives to tell when, or how often, the characteristic is applicable.

Examples:

He is very tall. (degree)

She was extremely sad. (degree)

The banker is usually punctual. (frequency)

The food is always delicious. (frequency)

The generator was previously functional. (time)