Here's why:
* Articles (like "a", "an", and "the") are words that precede nouns and specify whether the noun is singular or plural, and definite or indefinite.
* Adjectives modify nouns, describing their qualities.
* Adverbs modify verbs, adjectives, or other adverbs, describing how, when, where, or to what extent something happens.
Let me know if you'd like more examples!