Here's why:
* Adjectives describe nouns (people, places, things).
* Adverbs describe verbs, adjectives, or other adverbs. They tell us how, when, where, or to what extent something is done.
Example:
* Tonight is a cold night.
* "Cold" is the adjective describing the noun "night".
* "Tonight" tells us *when* the night is cold, making it an adverb.
Let me know if you have any other words you'd like to classify!