When do you use more and most instead of -er and -est?

With longer adjectives. One-syllable words take endings (faster, oldest); words of three or more syllables take more/most (more colorful, most interesting); two-syllable words split, and the ear usually knows (happier works, "more happy" sounds padded). Colorfuler is the classic trap answer.

Why is "more taller" wrong?

Because it doubles the comparison; taller already contains the "more." English takes one comparative per adjective, either the ending or the word, never both. Kids stop making this error quickly once someone names it, which is exactly what the answer key does.

3rd grade comparative and superlative adjectives

3rd grade comparative and superlative adjectives worksheets

Comparative adjectives (-er, or more) compare two things; superlatives (-est, or most) crown a winner among three or more. Third graders handle spelling changes along the way (big/bigger, happy/happiest) and learn which adjectives take more/most instead.

Free printable PDF worksheet, aligned to Common Core L.3.1.g.

Each print is a different sheet with its own answer key. You don't need to sign up.

The kind of sentences you'll fix

Write the form of the adjective in parentheses that fits the sentence.

Of all the puppies in the litter, the spotted one seems the (happy).
Fixed: Of all the puppies in the litter, the spotted one seems the happiest.
This peach tastes (sweet) than that apple.
Mount Wilson is the (high) of all three peaks.

Every print pulls a new set of sentences at this level, so a make-up test or a second sibling gets a different mix.

What's on a 3rd grade sheet

3rd grade sheets draw from 80 sentences, 8 to a page. All 60 of 2nd grade's sentences are here too, plus 20 more. 2nd grade sheets print 7 to a page.

A few of the sentences, as the answer key corrects them:

The oak tree is older than the house beside it.
Noor’s kick was higher than the crossbar.
Our team’s cheer was the loudest of all four teams.

Fix it. Write the form of the adjective in parentheses that fits the sentence. 8 sentences to fix per page.
Choose the word. Circle the letter of the form that fits the comparison. 10 questions per page.

Every version prints on US Letter or A4, with its answer key on the last page.

How to teach this

The spelling changes deserve their own pass: consonant doubling (big/bigger), y to i (happy/happiest), silent-e words (nice/nicer). Then introduce the syllable rule of thumb: short adjectives take endings, longer ones take more/most. "More prettier" style doubling is the top error at this level; naming it directly helps kids catch themselves.

Watch for: Long adjectives use more and most instead of -er and -est: more colorful, most interesting, never colorfuler. Never double up: 'more taller' and 'most fastest' are always wrong.

Common questions about 3rd grade comparative and superlative adjectives

When do you use more and most instead of -er and -est?: With longer adjectives. One-syllable words take endings (faster, oldest); words of three or more syllables take more/most (more colorful, most interesting); two-syllable words split, and the ear usually knows (happier works, "more happy" sounds padded). Colorfuler is the classic trap answer.
Why is "more taller" wrong?: Because it doubles the comparison; taller already contains the "more." English takes one comparative per adjective, either the ending or the word, never both. Kids stop making this error quickly once someone names it, which is exactly what the answer key does.

Related worksheets

Ready to print one?

Need a fresh set of sentences? Download another copy.

Aligned to Common Core L.3.1.g. Reviewed by the One more sheet team. Content version 240, updated October 2026.

Spot a mistake on this sheet? Tell us. · About these worksheets