Adverbs modify verbs. But they also modify adjectives and other adverbs, indicating "when" "in what way," and "to what degree." For example
- He drove frantically.
- The air was strangely silent.
- He drove very frantically
In the first and last sentences, the adverb frantically modifies the verb drove. In the second sentence, strangely modifies the adjective silent. Note that in the third sentence, the adverb frantically is modified by the adverb very.
When you are describing something in a positive way, remember that good is an adjective, but well is in adverb. Thus, one of these sentences is incorrect :
- I sing good
- I sing well
- I am a good singer.
The first one is wrong : the adjective good cannot modify the verb sing. Here is a contrasting example :
This works fine. Now, the adjective good modifies the noun singer.
Sumber : https://students.case.edu/education/peer/sagesguide/grammar/speech1.html
