Adjective vs Adverb

Adjectives describe nouns, while adverbs describe verbs, adjectives, or other adverbs. At the mastery level, you will learn to handle tricky cases where choosing the wrong form changes the meaning of a sentence or makes it grammatically incorrect.

What You'll Learn

In this lesson, you will learn:

How to choose correctly between adjective and adverb forms in complex sentences
Why "He runs quickly" is correct but "He runs quick" is wrong
How to handle confusing pairs like good/well, bad/badly, hard/hardly, and late/lately
When adverbs modify adjectives or other adverbs, not just verbs

When to Use

After action verbs, use an adverb: "The athlete completed the race quickly." (Quickly describes how he completed the race.)
After linking verbs, use an adjective: "The experiment results appeared accurate." (Accurate describes the results, not the action.)
Before an adjective, use an adverb: "The documentary was incredibly moving." (Incredibly modifies the adjective "moving".)
Before another adverb, use an adverb: "She solved the equation remarkably quickly." (Remarkably modifies the adverb "quickly".)
When the meaning changes with form: "He worked hard all evening." vs "He hardly worked at all." (These mean opposite things!)

How to Form

Deciding Between Adjective and Adverb

Ask yourself two questions to choose the correct form:

Step	Question to Ask	If Yes, Use	Example
1	Does the word describe a noun or pronoun?	Adjective	The careful student checked her work.
2	Does the word describe a verb, adjective, or adverb?	Adverb	The student checked her work carefully.

Tricky -ly Pairs with Different Meanings

Some words change meaning completely when you add -ly. These are not simply adjective-adverb pairs -- they are different words:

Without -ly	Meaning	With -ly	Meaning
hard	with great effort	hardly	almost not at all
late	not on time	lately	recently
near	close in distance	nearly	almost
high	at a great height	highly	to a great degree / very much
short	not long/tall	shortly	soon / in a brief time
free	without cost / unrestricted	freely	without restriction / willingly

Adverbs That Modify Adjectives or Other Adverbs

Adverbs do not only modify verbs. They also strengthen or weaken adjectives and other adverbs:

Structure	Example	What the Adverb Modifies
Adverb + Adjective	The question was extremely difficult.	"extremely" modifies the adjective "difficult"
Adverb + Adverb	She spoke unusually softly.	"unusually" modifies the adverb "softly"
Adverb + Past Participle	The book was well written.	"well" modifies the participle "written"

Key Rules

Action verbs take adverbs: When a verb shows an action (run, speak, write, eat), describe it with an adverb. "The choir sang beautifully." Not "The choir sang beautiful."
Linking verbs take adjectives: Verbs like is, am, are, was, were, seem, appear, look, feel, taste, smell, sound, become, and remain are linking verbs. The word after them describes the subject (a noun), so use an adjective. "The durian smelled strong." Not "The durian smelled strongly."
Some verbs can be linking or action verbs: The same verb can work both ways depending on meaning. "She looked happy." (linking -- describes her) vs "She looked carefully at the map." (action -- describes how she looked). Ask: is the verb describing a state or an action?
"Good" is always an adjective; "well" is usually an adverb: "She plays the piano well." (adverb, describes how she plays) vs "She is a good pianist." (adjective, describes the pianist). Exception: "well" can be an adjective meaning "healthy" -- "I don't feel well."
Do not confuse hard/hardly, late/lately, near/nearly: These pairs have completely different meanings. "He studied hard." (with effort) vs "He hardly studied." (almost did not study). Always check whether you mean the original word or the -ly version.
Adverbs of degree come before the word they modify: Words like very, extremely, quite, rather, incredibly, and remarkably are placed directly before the adjective or adverb they modify. "The hawker centre was extremely crowded." Not "The hawker centre was crowded extremely."

Common Mistakes

Wrong	Right	Why
He runs quick.	He runs quickly.	"Runs" is an action verb, so use the adverb "quickly"
The soup tasted deliciously.	The soup tasted delicious.	"Tasted" is a linking verb here, so use the adjective
She did good on the science test.	She did well on the science test.	"Did" is an action verb, so use the adverb "well"
I can't hardly wait for the holidays.	I can hardly wait for the holidays.	"Can't hardly" is a double negative; use "can hardly"
He has been working very hardly.	He has been working very hard.	"Hardly" means "almost not at all"; the adverb form of "hard" (effort) is "hard"
She sang so beautiful that everyone clapped.	She sang so beautifully that everyone clapped.	"Sang" is an action verb; "beautifully" is the adverb form needed here

Clue Words

Signals that you need an adjective

is, am, are, was, were, seem, appear, become, remain, look, feel, taste, smell, sound

These are linking verbs. The word after them describes the subject (a noun), so choose the adjective form.

Signals that you need an adverb

runs, walks, speaks, writes, sings, studies, eats, plays, works, reads, drove, finished, completed

These are action verbs. The word after them describes how the action is done, so choose the adverb form.

Words that signal an adverb is modifying another word

very, so, too, quite, rather, extremely, incredibly, remarkably, unusually, absolutely

These adverbs of degree modify adjectives or other adverbs -- never nouns.

Tip: If you are unsure, try replacing the word with "good" or "well". If "good" fits, you need an adjective. If "well" fits, you need an adverb. For example: "She performed ___." Would you say "She performed good" or "She performed well"? "Well" sounds right, so you need an adverb.

Practice Tips

The replacement test: Replace the word in question with "good" (adjective) or "well" (adverb). Whichever sounds natural tells you which form to use. "The cake tastes ___." -- "good" fits, so use an adjective.
The linking verb check: If the verb can be replaced with "is" or "was" without changing the meaning, it is acting as a linking verb, so use an adjective. "The flowers smell sweet." -- "The flowers are sweet" works, so "sweet" (adjective) is correct.
The meaning check for tricky pairs: Before using a word ending in -ly, pause and check whether it means the same as the base word. "He arrived late" (not on time) and "He has been busy lately" (recently) mean very different things. Choose based on your intended meaning.
The "how?" test for adverbs modifying adverbs: If a sentence has two describing words together, ask whether the first one answers "how?" about the second. "She spoke remarkably clearly." How clearly? Remarkably clearly. Both are adverbs working together.

Quick Reference