Adjectives and adverbs
Adjectives describe nouns; adverbs describe verbs, adjectives and other adverbs.
Updated October 29, 2026
The rule
How did someone do something? Use an adverb, usually ending in -ly: she sang beautifully, he drove carefully.
Good is an adjective (a good game); well is the adverb (she played well). Real is an adjective; really is the adverb (really fast).
Examples
She did good on the test.She did well on the test.He runs real fast.He runs really fast.
Quick test: Find the word being described. A verb (runs, did) needs an adverb.
Try it: find the mistake
The mistake in each sentence is highlighted. Say the fix out loud, then open the answer.
The turtle moved very slow.
The turtle moved very slowly.
Slow describes how it moved (a verb), so use the adverb slowly.
You sing really good.
You sing really well.
Good describes things; well describes how you do something.
The soup smelled deliciously.
The soup smelled delicious.
Smell, taste, look and feel link the subject to a describing word, so use the adjective: delicious.
He finished the race real quickly.
He finished the race really quickly.
Really describes the adverb quickly, so it must be an adverb.
Where this rule is tested
Questions people ask
What is the rule for adjectives and adverbs?
Adjectives describe nouns; adverbs describe verbs, adjectives and other adverbs. How did someone do something? Use an adverb, usually ending in -ly: she sang beautifully, he drove carefully.
How can I check my adjectives and adverbs quickly?
Find the word being described. A verb (runs, did) needs an adverb.
Where can I practice this for free?
In Owl Test Prep's Daily Grammar Fix: one sentence a day for everyone, plus practice sets of five on this rule. It is free, with no account.