Understanding prefixes, suffixes, and roots can help determine the meaning of new words. Prefixes are added before words to alter meaning, suffixes are added after, and roots convey basic meaning. Common examples are provided.

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.