Here's a breakdown:
* Adjectives describe nouns. They answer questions like "What kind?" or "Which one?". Examples: "quick" (describing a fast movement), "slow" (describing a sluggish movement).
* Adverbs modify verbs, adjectives, or other adverbs. They answer questions like "How?" "When?" "Where?" "To what extent?". Examples: "quickly" (describes how something moves), "slowly" (describes how something moves), "very" (describes the extent of something).
So, "quickly" is the adverb form of the adjective "quick". It tells you how something is done, while "quick" describes the action itself.