1. Prefixes, Suffixes, and Roots

2. Why learn about prefixes, suffixes, and roots?
• Understanding prefixes, suffixes, and roots can
help you to determine the meaning of new
and unfamiliar words as you come across
them while reading.

3. Prefixes
• A prefix is a group of letters added before a
word or base to alter its meaning and form a
new word.

4. The most common prefixes
(with their meaning in parenthesis)
• dis- (not, opposite of) Ex. disagree, discomfort
• in-, im-, il-, ir- (not) Ex. injustice, impossible,
illegal, irregular
• re- (again) Ex. rewrite, return, repeat
• un- (not) Ex. unfriendly, unsure

5. Suffix
• A suffix is a group of letters added after a
word or base and form a new word.

6. The most common suffixes
(with their meaning in parenthesis)
• -ed (past tense verbs) Ex. jumped, hopped
• -ing (present participle) Ex. running, eating
• -or, -er (one who) Ex. actor, teacher, driver
• -less (without) Ex. fearless, hopeless
• -logy (study field of) Ex. biology, geology
• -s, -es (more than one) Ex. books, boxes

7. Root words
A root is the most basic form of a word that is
able to convey a particular meaning.
• aud (sound) – Ex. audible, audiotape
• bio (life) – Ex. autobiography, biology
• meter (measure) – Ex. thermometer, odometer
• port (carry) – Ex. transport, portable

8. To summarize
• Prefixes and suffixes are groups of letters
added before or after words or roots to form
new words with different meanings.
• Understanding prefixes, suffixes, and roots can
help you to determine the meaning of new
and unfamiliar words as you come across
them while reading.