Here's why:
* Adverbs primarily modify verbs: They tell us how, when, where, or to what extent an action is performed.
* Example: "He ran quickly." (modifies the verb "ran")
* Adverbs can also modify adjectives: They can provide more information about the adjective, describing its intensity or degree.
* Example: "The house was incredibly beautiful." (modifies the adjective "beautiful")
Other parts of speech can also modify verbs and adjectives, but not as commonly:
* Prepositional phrases: "He walked through the park." (modifies "walked")
* "She was very happy with the results." (modifies "happy")
* Adjective clauses: "The man who was wearing a blue hat walked by." (modifies "man")
* "The book that I read last night was fascinating." (modifies "book")
Let me know if you have any other linguistic mysteries you want to solve!