Here's why:
* Adverbs modify verbs: They describe how, when, where, or to what extent an action is performed. For example:
* "He quickly ran to the store." (How did he run?)
* "She always eats breakfast." (When does she eat breakfast?)
* Adverbs can also modify adjectives: They can describe the degree or intensity of the adjective. For example:
* "The room was incredibly clean." (How clean was the room?)
* "She is very happy." (How happy is she?)
While adverbs are known for modifying verbs, their ability to modify adjectives expands their grammatical role and adds complexity to sentence structure.