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Adjectives vs Adverbs for ACT English: Grammar Rule

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Posted by Justin Berkman | Jun 30, 2015 11:52:49 PM

ACT English



You may recall the good ol’ days of elementary school when you learned about adjectives and adverbs. If you had realized that you would have to know about these parts of speech for the ACT, perhaps you would have paid better attention instead of daydreaming about Nickelodeon and The Disney Channel. Don’t worry. If you’ve forgotten or never learned about these parts of speech, I’ll teach you everything you need to know about them for the ACT English section.

In this post, I'll do the following:

  • Define an adjective.
  • Define an adverb.
  • Review the comparative and superlative forms of adjectives.
  • Explain how adjectives and adverbs are tested in ACT English.
  • Provide practice questions to test you on what you've learned.


What Is an Adjective?

Adjectives modify nouns or pronouns. Here's an example:

The movie was boring.


The word "boring" is the adjective because it modifies the noun "movie." Check out one more example sentence with an adjective:

The diligent student was admitted to the college of his dreams.


The word "diligent" modifies the noun "student." Adjectives describe or provide more information about a noun.

Now, let's define an adverb.


What is an Adverb?

In elementary school, you may have learned that adverbs modify verbs, but that's not all. Adverbs modify verbs, adjectives, or other adverbs. This is an example of an adverb modifying a verb:

The dancer moved gracefully.


The word "gracefully" modifies the verb "moved." Check out this sentence with an adverb modifying an adjective:

The reading comprehension passage was incredibly boring.


The word "incredibly" modifies the adjective "boring" that modifies the noun "passage." And, finally, this is a sentence with an adverb modifying another adverb:

When I'm not in a hurry, I walk extremely slowly.


The word "extremely" modifies the adverb "slowly." The word "slowly" modifies the verb "walk."

You may have noticed the adverb form is typically created the same way.


Adverb Construction

Adverbs are usually formed by adding "ly" to the adjective. For adverbs that end in "y," the adverb is formed by adding "ily." Here are some examples: "quick" becomes "quickly," "soft" becomes "softly," "close" becomes "closely," and "hasty" becomes "hastily."  So if you say that somebody "talks slow" or "drives careful," you're making a grammar error. You should say, "talks slowly" or "drives carefully."

How are adjectives and adverbs tested on the ACT?


Adjectives vs. Adverbs on the ACT

On the ACT, adverbs and adjectives will be switched with one another. Often, you will be given a pair of underlined words and the first should be an adverb (modifying the adjective) and the second should be an adjective. Here is an example:

Unfortunately, the lead performer in the musical is an amazingly poorly singer.

B. amazing poorly
C. amazingly poor
D. amazing poor


In the sentence, "amazingly" modifies "poorly." The word "poorly" modifies the singer. Because "singer" is a noun, "poorly" should be in the adjective form. Only adjectives can modify nouns. Because "amazingly" modifies an adjective, it should remain in the adverb verb. The answer is C.

Some sentences will use an adjective in the place of an adverb or vice versa:

The powerfully summer sun beat down on them.


It was the sun that was powerful, not "summer." Because only an adjective can modify a noun, "powerfully" should be in the adjective form. This is the correct version of the sentence:

The powerful summer sun beat down on them.




How should you go about figuring out adjective vs. adverb questions on the ACT?



Determine what word an adjective or adverb is modifying. Then, determine the part of speech of the word that is being modified to check to see if the adjective or adverb is being used correctly. Adjectives can only modify nouns and adverbs can only modify verbs, adjectives, or other adverbs. Make sure that adjectives are in the adjective form and adverbs are in the adverb form.


Apply these tips to an adjective vs. adverb question from an actual ACT.


Actual ACT Examples

Try to correctly answer this adjective vs. adverb question.

On each wing, all flighted birds have ten primary flight feathers, each one shaped slight different.

G. slight differently.
H. slightly differently
J. slightly more different


Explanation: First, we see that both underlined words are in the adjective form. Next, we have to determine the function of each word in the sentence. Is each word being properly used as an adjective? Let’s start with “different." What is “different” modifying? How the feathers were shaped. “Shaped” is a verb. Therefore, “different” should be in the adverb form, “differently." What is “slight” modifying? The adverb “differently." Therefore, “slight” should also be in the adverb form. The answer is H, “slightly differently."

Now, let's take a look at another issue tested on the ACT that involves adjectives and adverbs.


Comparatives Vs. Superlatives



The comparative form of an adjective is formed by adding "er" to the word or "MORE" + the adjective. Examples of comparatives include "stronger," "lighter," and "more interesting." Never use "more" with the "er" form. You can't write "more stronger" or "more lighter." The comparative form is only used when you are comparing two things.

Typically, you use the "er" form for words with one syllable and "more" + adjective for words with two or more syllables. One exception is that two syllable words that end in "y" tend to use the "er" form. Examples: "funny" becomes "funnier" and "busy" becomes "busier." Here's an example of a comparative being used correctly:

Macs are easier to use than PCs.


The comparative "easier" is being used to compare two things: Macs and PCs. So what form do you use to compare three or more things?



The superlative form of an adjective is formed by adding "est" to the word or "MOST" + the adjective. Examples of superlatives include "strongest," "lightest," and "most fascinating." You can never use "most" with the "est" form. It's incorrect to write "most funniest" or "most strongest." The superlative form is only used when comparing three or more things. Typically, words with one syllable use the "est" form and words with two or more syllables use "most" + adjective. This is an example of a correctly used superlative:

Of all the computer brands, Macs are the easiest to use.


When using "all" and not specifying a number, it's implied that you're talking about more than two so you should use the superlative form. Check out this example of a superlative being used incorrectly:

Between John and Suzy, Suzy is the quietest.


Remember that the superlative can only be used when comparing three or more things. There are only two in this sentence: John and Suzy. To fix the error, "quietest" should be changed to the comparative form, "quieter."

How does the ACT test your knowledge of comparatives and superlatives?


Comparatives and Superlatives on the ACT

The ACT tests proper construction of comparatives and superlatives. You must know that comparatives are only used for comparing two things and superlatives are used for comparing three or more.

Here are some tips to help you solve comparative and superlative questions on the ACT.



Comparative and superlative rules are relatively basic. Remember this information and you should be able to correctly answer any ACT English question about them.

If a comparative is underlined, make sure only two things are being compared. Never use "more" with the "er" form. Use the "er" form for one syllable words. If a superlative is underlined, make sure three or more things are being compared. Never use "most" with the "est" form. Use the "est" form for one syllable words.

Use your knowledge of comparatives and superlatives to answer this real ACT English question.


Actual ACT Example

Here is a comparative/superlative question taken from a real ACT.

The two principal types of kayaks are the easily maneuverable white-water kayak and the largest sea kayak.

             F. NO CHANGE
            G. very biggest
          H. more large
 J. larger


Explanation: Because the word underlined is in the superlative form, we need to check to see if the superlative form is being used correctly. What is being compared in the sentence? The white-water kayak and the sea kayak.

Only two things are being compared, so you have to use the comparative form. The sentence even says, “The TWO principal types of kayaks." Also, “large” is a one syllable word so you should use the “er” form instead of “more large." The answer is J.

Here are some tips to help you answer all questions relating to adjectives and adverbs on the ACT.


General Strategies for Adjectives and Adverbs on ACT English


#1: If an Adjective or Adverb is Underlined, Make Sure the Word is Being Used Correctly

On the ACT, adjectives and adverbs will often be placed next to each other and both words will be underlined. Make sure that adjectives are in adjective form and adverbs are in adverb form.


#2: Determine the Part of Speech of the Word that the Adjective or Adverb Is Modifying

Determine if a word is an adjective or an adverb by identifying the part of speech of the word it modifies. Adjectives modify nouns and adverbs modify verbs, adjectives, and other adverbs.


#3: If a Comparative or Superlative Is Underlined, Make Sure the Word Is Being Used Correctly



Comparatives only compare two things. Proper comparative structure is the "er" form or "MORE" + adjective. Never use "MORE" with the "er" form. Use the "er" form for one syllable words.



Superlatives compare three or more things. Proper superlative construction is the "est" form or "MOST" + adjective. Never use "MOST" with the "est" form. Use "est" for one syllable words.




Additional Practice

I created these realistic practice problems to test your knowledge of adjectives and adverbs on the ACT. Enjoy!


1. The young student was disillusioned with school; he found his classes boring, and he thought economics was his most boringly class.

B. most boring
C. more boring
D. more boringly


2. Because my friend is better at math than I am, he can more easily solve complex trigonometry questions. 
B. more easier
C. most easy
D. easily


3. Chris Farley was a very gifted entertainer who left an extremely profound impact on Saturday Night Live.

B. extremely profoundly
C. extreme profound
D. extreme profoundly


4. Joe decided to attend Stanford because it was the more prestigious school that accepted him.

B. more prestigiously
C. most prestigious
D. most prestigiously
Answers: 1. B, 2. A, 3. A, 4. C


What's Next??

Keep improving the skills that will help you master the ACT English section. Read this article about the best way to approach ACT English.

For those of you focusing on learning ACT grammar, I highly you recommend you check out these posts on faulty modifiers and punctuation.

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Justin Berkman
About the Author

Justin has extensive experience teaching SAT prep and guiding high school students through the college admissions and selection process. He is firmly committed to improving equity in education and helping students to reach their educational goals. Justin received an athletic scholarship for gymnastics at Stanford University and graduated with a BA in American Studies.

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