Root Words and Affixes
Grade 5 · English · Study Guide
Build your vocabulary by understanding how prefixes, root words, and suffixes combine to create meaning.
A root word is the base part of a word that carries its core meaning. Many English words come from Latin and Greek roots. If you know common roots, you can figure out the meaning of hundreds of unfamiliar words.
An affix is a word part added to a root. Prefixes are added to the beginning of a word and change its meaning (e.g., 'un-' means not). Suffixes are added to the end and often change a word's part of speech (e.g., '-ful' means full of).
For example, knowing that 'port' means 'carry' helps you understand transport (carry across), portable (able to be carried), and export (carry out). Affixes multiply the power of every root you learn.
| Prefix | Meaning | Example |
|---|---|---|
| un- | not | unhappy |
| re- | again | rewrite |
| pre- | before | preview |
| mis- | wrongly | misread |
| dis- | not / opposite | disagree |
| Root | Meaning | Example Words |
|---|---|---|
| port | carry | transport, portable, import |
| scrib/script | write | describe, script, inscription |
| aud | hear | audible, audience, audio |
| vis | see | vision, visible, revise |
| dict | say/tell | predict, dictionary, dictate |
Key terms
- Root Word
- The base part of a word that carries the core meaning
- Prefix
- A word part added to the beginning that changes the meaning (e.g., un-, re-, pre-)
- Suffix
- A word part added to the end that changes the meaning or part of speech (e.g., -ful, -less, -tion)
- Affix
- A general term for any word part added to a root (includes prefixes and suffixes)
Practice questions
What does the prefix 're-' mean?
- Not
- Before
- Again
- Under
Show answer
'Re-' means again — rewrite means to write again, redo means to do again.
The root 'aud' means hear. Which word uses this root?
- Auditorium
- Automatic
- Autumn
- August
Show answer
Auditorium contains the root 'aud' (hear) — it's a place designed for people to listen.
A _______ is a word part added to the beginning of a root word to change its meaning.
Show answer
Prefixes come before the root word and alter its meaning (e.g., 'un-' + 'happy' = unhappy).
What does the word 'invisible' mean? (Root: 'vis' = see; Prefix: 'in-' = not)
- Very visible
- Easy to see
- Not able to be seen
- Able to see far
Show answer
'In-' (not) + 'vis' (see) + '-ible' (able to be) = not able to be seen.
Which suffix makes a word mean 'full of'?
- -less
- -ful
- -tion
- -er
Show answer
The suffix '-ful' means full of — thankful means full of thanks, hopeful means full of hope.
Fun facts
- About 60% of English words have Latin or Greek roots — knowing just 20 roots can help you decode over 100,000 words.
- The root 'geo' (meaning earth) shows up in geography, geology, geometry, and even the word 'George.'
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