Comparison of adjectives and adverbs

Q: How do you form comparative and superlative degrees for one-syllable adjectives?

Add -er and -est to the base word; add only -r and -st if it ends in -e , and double the final consonant if it follows the C-V-C pattern.

Q: How do you form the comparative and superlative of a two-syllable adjective ending in -y ?

Change the final -y to an -i , then add -er for the comparative and -est for the superlative.

Q: How do you form the comparative and superlative for long adjectives of two or more syllables?

Place more before the adjective for the comparative degree, and the most before it for the superlative degree.

Q: What are the comparative and superlative forms of the irregular adjectives good , bad , and far ?

Good becomes better / the best ; bad becomes worse / the worst ; far becomes farther (further) / the farthest (furthest) .

Q: How are adverbs ending in -ly compared?

Use more before the adverb for the comparative degree and the most before the adverb for the superlative degree.

Q: How do you compare short adverbs that share the same form as adjectives, such as fast and hard ?

Compare them by adding -er for the comparative degree and -est for the superlative degree, just like short adjectives.

Q: What are the comparative and superlative forms of the irregular adverbs well and badly ?

Well becomes better / the best , and badly becomes worse / the worst .

Q: What structure is used to make equal and unequal positive comparisons?

Use as + base adjective/adverb + as for equal comparisons, and not as + base adjective/adverb + as for unequal comparisons.

English · Lower Secondary · 8 min read · Updated: 22 Oct 2026

Comparison of Adjectives and Adverbs

Welcome to your study guide on Comparison of Adjectives and Adverbs! Have you ever wanted to explain why one food stall serves tastier noodles than another, who runs the fastest in your class, or why today feels as hot as yesterday? In English, we use comparison structures every single day to describe the world around us, share opinions, and make everyday choices.

Don't worry if grammar rules sometimes feel confusing or overwhelming. We will take this step by step, using clear rules, helpful examples, and simple memory tricks so you can master comparisons with confidence!

Quick Check: Adjective vs. Adverb

Before we start comparing, let's do a quick refresher on the difference between an adjective and an adverb.

• An adjective describes a noun (a person, animal, place, or thing). It tells us which one, what kind, or how many.
Example: Somchai is a fast runner. (Here, fast describes the runner.)

• An adverb describes a verb (an action). It tells us how, when, or where an action happens.
Example: Somchai runs fast. (Here, fast describes the action of running.)
Example: Malee sings sweetly. (Here, sweetly describes how she sings.)

Key Takeaway: Adjectives describe things; adverbs describe actions!

The Three Degrees of Comparison

In English, we compare people, objects, and actions across three levels (or "degrees"):

1. Positive Degree (Equal Comparison): Used when two things or actions are the same or equal.
Pattern: as + adjective/adverb + as
Example: My school bag is as heavy as yours.
Example: Kanda reads as quickly as her brother.

2. Comparative Degree: Used to compare two people, items, or actions to show which one has more of a quality.
Pattern: adjective-er + than OR more + adjective/adverb + than
Example: A bicycle is slower than a motorcycle.
Example: Anucha speaks English more fluently than I do.

3. Superlative Degree: Used to compare three or more people, items, or actions to show which one is at the absolute top or bottom.
Pattern: the + adjective-est OR the most + adjective/adverb
Example: Mount Everest is the highest mountain in the world.
Example: Lek worked the most carefully of all the students.

Comparing Adjectives: Step-by-Step Rules

To choose between adding -er / -est or using more / most, look at how many syllables (sound beats) the adjective has.

1. One-Syllable Adjectives (Short Words)

For short words that have only one beat of sound, we usually add -er for the comparative and -est for the superlative.

• General Rule: Just add -er and -est.
tall \(\rightarrow\) taller \(\rightarrow\) the tallest
small \(\rightarrow\) smaller \(\rightarrow\) the smallest
cold \(\rightarrow\) colder \(\rightarrow\) the coldest
Sentence: Chiang Rai is colder than Bangkok in December.

• Ending in -e: Just add -r and -st.
large \(\rightarrow\) larger \(\rightarrow\) the largest
safe \(\rightarrow\) safer \(\rightarrow\) the safest

• Double the Final Consonant (C-V-C Rule): If a short word ends in one consonant + one vowel + one consonant, double the last letter before adding -er or -est.
big \(\rightarrow\) bigger \(\rightarrow\) the biggest
hot \(\rightarrow\) hotter \(\rightarrow\) the hottest
thin \(\rightarrow\) thinner \(\rightarrow\) the thinnest
Sentence: April is usually the hottest month of the year in Thailand.

2. Two-Syllable Adjectives Ending in -y

If an adjective has two syllables and ends in the letter -y, change the -y to an -i, then add -er or -est.

• happy \(\rightarrow\) happier \(\rightarrow\) the happiest
• easy \(\rightarrow\) easier \(\rightarrow\) the easiest
• heavy \(\rightarrow\) heavier \(\rightarrow\) the heaviest
• noisy \(\rightarrow\) noisier \(\rightarrow\) the noisiest
Sentence: This science quiz was easier than last week's test.

3. Long Adjectives (Two or More Syllables without -y)

When an adjective is two syllables (not ending in -y) or three syllables or longer, do not add -er or -est. Instead, place more before the word for comparatives, and the most for superlatives.

• modern \(\rightarrow\) more modern \(\rightarrow\) the most modern
• famous \(\rightarrow\) more famous \(\rightarrow\) the most famous
• expensive \(\rightarrow\) more expensive \(\rightarrow\) the most expensive
• beautiful \(\rightarrow\) more beautiful \(\rightarrow\) the most beautiful
Sentence: Plane tickets are usually more expensive than bus tickets.
Sentence: Which phone in the shop is the most expensive?

4. Irregular Adjectives (Special Changes)

Some common adjectives do not follow any regular spelling pattern. You will want to memorise these, as they appear frequently in class tests and daily conversation!

• good \(\rightarrow\) better \(\rightarrow\) the best
Example: Fresh fruit is better for your health than candy.
Example: She is the best swimmer on our school team.

• bad \(\rightarrow\) worse \(\rightarrow\) the worst
Example: Today's traffic is worse than yesterday's.
Example: That was the worst storm of the rainy season.

• far \(\rightarrow\) farther / further \(\rightarrow\) the farthest / furthest
Example: My home is farther from school than yours.

Key Takeaway: Short words take -er/-est. Long words take more/most. Irregulars (good, bad, far) change their whole spelling!

Comparing Adverbs: How Actions Differ

Adverbs tell us how someone does something. Comparing adverbs follows a very neat and simple system.

1. Adverbs Ending in -ly

Most adverbs are formed by adding -ly to an adjective (e.g., careful \(\rightarrow\) carefully, quick \(\rightarrow\) quickly). For these adverbs, always use more for comparative and the most for superlative.

• quickly \(\rightarrow\) more quickly \(\rightarrow\) the most quickly
• carefully \(\rightarrow\) more carefully \(\rightarrow\) the most carefully
• loudly \(\rightarrow\) more loudly \(\rightarrow\) the most loudly
Sentence: Please write more carefully than you did on the draft.
Sentence: Among all the students, Suda answered the most politely.

2. Short Adverbs (Same Form as Adjectives)

A few common adverbs do not end in -ly. They look identical to one-syllable adjectives. For these, use -er and -est just like short adjectives!

• fast \(\rightarrow\) faster \(\rightarrow\) the fastest
• hard \(\rightarrow\) harder \(\rightarrow\) the hardest
• early \(\rightarrow\) earlier \(\rightarrow\) the earliest
• late \(\rightarrow\) later \(\rightarrow\) the latest
Sentence: Piti works harder than anyone else on the group project.
Sentence: Who arrived at the classroom the earliest this morning?

3. Irregular Adverbs

Just like adjectives, a couple of very important adverbs have irregular forms:

• well (the adverb of good) \(\rightarrow\) better \(\rightarrow\) the best
Example: She plays badminton better than her brother.
Example: He spoke the best during the presentation.

• badly (the adverb of bad) \(\rightarrow\) worse \(\rightarrow\) the worst
Example: Our team played worse than last week.

Did You Know? Be careful with good and well! We say: "He is a good singer" (adjective describing the person), but "He sings well" (adverb describing the singing action). Both change to better in the comparative degree!

Making Equal Comparisons: "as... as"

When two people, items, or actions have the same degree of a quality, we place the basic adjective or adverb between as and as.

Equal (Affirmative)

Pattern: as + base adjective/adverb + as
• This green apple is as sweet as that red one.
• Wichai can run as fast as Danai.

Not Equal (Negative)

To say that one thing does not have as much of a quality as another, we use not as... as.
Pattern: not as + base adjective/adverb + as
• Travelling by bus is not as fast as travelling by train.
(This means the train is faster than the bus!)
• I do not sing as clearly as my teacher.

Important Tip: Never put -er or more inside an as...as structure! Always use the base form.
Correct: as tall as
Incorrect: as taller as

Common Mistakes to Avoid

Here are four classic errors students often make on quizzes. Keep an eye out for them!

1. Double Comparatives (The "More -er" Trap):
Do not use more and -er together on the same word.
• Incorrect: Today is more hotter than yesterday.
• Correct: Today is hotter than yesterday.

2. Double Superlatives (The "Most -est" Trap):
Do not use most and -est together.
• Incorrect: He is the most tallest boy.
• Correct: He is the tallest boy.

3. Forgetting "than" in Comparatives:
When stating both items being compared, remember to include than (spelled with an a, not then with an e).
• Incorrect: My dog is bigger then your dog.
• Correct: My dog is bigger than your dog.

4. Forgetting "the" in Superlatives:
Because the superlative indicates a unique, top-ranking item, always include the before the superlative form.
• Incorrect: She is fastest student in school.
• Correct: She is the fastest student in school.

Summary and Quick Review Checklist

Before your exam, test yourself with this quick checklist:

• Positive / Equal: Use as + base form + as (e.g., as cold as, as carefully as).
• Comparative (2 items):
- 1 syllable: add -er + than (e.g., faster than, bigger than).
- 2 syllables ending in -y: change to -ier + than (e.g., happier than).
- 2+ syllables or adverbs ending in -ly: use more + word + than (e.g., more expensive than, more quietly than).
• Superlative (3+ items):
- 1 syllable: use the + word-est (e.g., the fastest, the biggest).
- 2 syllables ending in -y: use the + word-iest (e.g., the happiest).
- 2+ syllables or adverbs ending in -ly: use the most + word (e.g., the most expensive, the most quietly).
• Irregulars:
- good / well \(\rightarrow\) better \(\rightarrow\) the best
- bad / badly \(\rightarrow\) worse \(\rightarrow\) the worst
- far \(\rightarrow\) farther / further \(\rightarrow\) the farthest / furthest

Quick check

Can you answer these now?

Open each question to check the key ideas from this chapter.

What is the main difference between an adjective and an adverb?

An adjective describes a noun (a person, place, or thing), whereas an adverb describes a verb (an action) by explaining how, when, or where it happens.

What are the three degrees of comparison in English?

The three degrees are the positive degree (equal comparison using as... as), the comparative degree (comparing two things), and the superlative degree (comparing three or more things).

How do you form comparative and superlative degrees for one-syllable adjectives?

Add -er and -est to the base word; add only -r and -st if it ends in -e, and double the final consonant if it follows the C-V-C pattern.

How do you form the comparative and superlative of a two-syllable adjective ending in -y?

Change the final -y to an -i, then add -er for the comparative and -est for the superlative.

How do you form the comparative and superlative for long adjectives of two or more syllables?

Place more before the adjective for the comparative degree, and the most before it for the superlative degree.

What are the comparative and superlative forms of the irregular adjectives good, bad, and far?

Good becomes better / the best; bad becomes worse / the worst; far becomes farther (further) / the farthest (furthest).

How are adverbs ending in -ly compared?

Use more before the adverb for the comparative degree and the most before the adverb for the superlative degree.

How do you compare short adverbs that share the same form as adjectives, such as fast and hard?

Compare them by adding -er for the comparative degree and -est for the superlative degree, just like short adjectives.

What are the comparative and superlative forms of the irregular adverbs well and badly?

Well becomes better / the best, and badly becomes worse / the worst.

What structure is used to make equal and unequal positive comparisons?

Use as + base adjective/adverb + as for equal comparisons, and not as + base adjective/adverb + as for unequal comparisons.

Why are phrases like "more hotter" or "the most tallest" grammatically incorrect?

They are double comparatives and double superlatives; you must use either an ending (-er / -est) or an auxiliary word (more / most), never both at the same time.

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