Adjectives describe nouns; adverbs modify verbs, adjectives, and other adverbs. Confusing them — especially with -ly adverbs and flat adverbs — is a persistent intermediate error. Some words (fast, hard, late, early) look identical as adjectives and adverbs, while others have irregular adverb forms (good → well).
Practice
She speaks English very. (good / well)
It was adecision to make. (adjective — modifies noun)
Sheever takes a day off. (hard / hardly = almost never)
He drives too.
This is acompetitive market.
You explained the process very.
I feelabout the mistake. (bad / badly — after feel)
The whole event wasorganized. (good / well)
She spoke so _____ that everyone understood immediately.
He's a _____ negotiator — he always gets what he wants.