Grade: Grade 3 Subject: SAT/ACT Skills Unit: Roots & Prefixes SAT: Craft+Structure ACT: Reading

Common Prefixes

Prefixes are like word superpowers! When you add a prefix to the beginning of a word, you can change its meaning completely. Learning prefixes will help you understand many new words!

What is a Prefix?

A Prefix is a Word Part Added to the Beginning!

A prefix is a group of letters that we add to the front of a word to change its meaning. Think of it like putting on a hat - the hat changes how you look!

🔤 How Prefixes Work

Every word with a prefix has two parts:

unhappy = unhappy

Prefix: un- (means "not")

Base Word: happy (feeling good)

New Word: unhappy (NOT feeling good)

Think About It: When you know what a prefix means, you can figure out the meaning of words you've never seen before! That's why learning prefixes is so powerful.

Six Common Prefixes to Know

Here are six important prefixes that you'll see in many words:

un-

Means: NOT

unfair = not fair

re-

Means: AGAIN

reread = read again

pre-

Means: BEFORE

preview = view before

dis-

Means: NOT or OPPOSITE

disagree = not agree

mis-

Means: WRONGLY

misspell = spell wrongly

non-

Means: NOT

nonfiction = not fiction

Prefix	Meaning	Example Words
un-	not, opposite of	unhappy, unlock, unsafe, unkind
re-	again, back	rewrite, redo, return, replay
pre-	before	preschool, preheat, prepay, preview
dis-	not, opposite of	dislike, dishonest, disappear, disobey
mis-	wrongly, badly	mistake, misread, misplace, misunderstand
non-	not	nonstop, nonsense, nonfat, nonprofit

How Prefixes Change Meaning

Watch how adding a prefix transforms the meaning of a word:

un- + happy = unhappy

happy (feeling joy) → unhappy (NOT feeling joy; sad)

re- + build = rebuild

build (make something) → rebuild (make something AGAIN)

pre- + heat = preheat

heat (make warm) → preheat (heat BEFORE cooking)

dis- + appear = disappear

appear (come into view) → disappear (go out of view; vanish)

mis- + spell = misspell

spell (write letters correctly) → misspell (spell WRONGLY)

non- + stop = nonstop

stop (pause or end) → nonstop (without stopping; continuous)

Reading Tip: When you see a long word you don't know, look for a prefix at the beginning! Cover the prefix and read the base word first. Then think about what the prefix means.

Word Builder Activity

Build new words by choosing a prefix and a base word. See how the meaning changes!

Click a Prefix and a Base Word to Build a New Word!

? + ?

Select a prefix and base word above!

Choose a Prefix:

Choose a Base Word:

Matching Game

Match each word to its correct meaning!

Click a word, then click its meaning to match!

Words

unlock

reread

preheat

disappear

misspell

Meanings

heat before

spell wrongly

not locked; open

go away from sight

read again

Matches: 0 / 5

Practice Problems

Test your knowledge of common prefixes!

Problem 1

What does the prefix un- mean?

Problem 2

If "rewrite" means "write again," what does "redo" mean?

Problem 3

The word "preheat" means to heat ______.

Problem 4

Which word means "to spell wrongly"?

Problem 5

What is the base word in "unhappy"?

Problem 6

If "nonstop" means "without stopping," what does "nonfiction" mean?

Check Your Understanding

Which prefix means "again"?

A prefix is added to which part of a word?

Both "un-" and "dis-" can mean:

What We Learned

🔤

Prefixes

Word parts added to the beginning that change meaning.

🚫

un-, dis-, non-

These prefixes mean "not" or "opposite of."

🔄

re-

This prefix means "again" or "back."

⏰

pre-

This prefix means "before."

❌

mis-

This prefix means "wrongly" or "badly."

💡

Word Power

Knowing prefixes helps you understand new words!

Keep Practicing! The more you practice spotting prefixes, the easier it becomes to figure out what new words mean. Look for these prefixes in books you read!

Next Steps

Look for words with prefixes when you read books and stories
Try to guess the meaning of new words by identifying the prefix
Make flashcards with prefixes and their meanings
Practice building new words by adding prefixes to base words