Word Knowledge
Prefixes, Suffixes & Roots
You will not know the meaning of every word on Word Knowledge. A prefix, suffix, or root can provide a clue that helps estimate meaning, eliminate wrong choices, recognize relationships, and make an educated guess.
Section 1
Common Prefixes
A prefix appears at the beginning of a word and can change its meaning. You do not need to memorize hundreds of prefixes; focus on common ones that regularly appear in English vocabulary. Word parts are clues, not guaranteed definitions. Always consider the entire word and the answer choices.
Prefix reference
| Word part | Meaning | Examples |
|---|---|---|
| un- | not; opposite of | unusual, unfair, uncertain |
| re- | again; back | rebuild, reconsider, return |
| pre- | before | preview, predict, prewar |
| post- | after | postwar, postgraduate |
| anti- | against; opposed to | antibiotic, antisocial, antiwar |
| sub- | under; below; less than | submarine, substandard, subway |
| super- | above; beyond | superhuman, superstructure |
| inter- | between; among | international, interact, interstate |
| intra- | within | intrastate, intramural |
| mis- | wrong; badly | misjudge, misunderstand, misplace |
| dis- | not; opposite; apart | disagree, disconnect, disapprove |
| non- | not | nonessential, nonviolent, nonfiction |
| bi- | two | bicycle, bilingual, biennial |
| tri- | three | triangle, tripod, tricycle |
| multi- | many; multiple | multicultural, multinational, multitask |
| semi- | half; partly | semicircle, semifinal, semiconscious |
| over- | too much; above | overestimate, overwork |
| under- | too little; below | underestimate, underpaid |
Example 1
Misinterpret most nearly means: A. understand incorrectly | B. explain clearly | C. repeat loudly | D. shorten greatly
Solution
- 1The prefix mis- often means wrong or incorrectly.
- 2The rest of the word relates to interpreting or understanding something.
- 3The likely meaning is understand incorrectly.
Why: The prefix mis- gives a strong clue that something is being done incorrectly.
Example 2
Substandard most nearly means: A. above average | B. below an accepted level | C. completely equal | D. newly created
Solution
- 1The prefix sub- can mean under or below.
- 2A standard is an accepted level.
- 3Substandard therefore means below the accepted standard.
Why: The prefix shows that the word describes something below the normal or expected standard.
Example 3
Multinational most nearly means: A. involving many nations | B. involving one neighborhood | C. against all nations | D. occurring before a nation forms
Solution
- 1The prefix multi- means many.
- 2National relates to nations.
- 3Multinational means involving many nations.
Why: Recognizing multi- narrows the meaning toward something involving more than one.
Section 2
Common Suffixes
A suffix appears at the end of a word. Suffixes can show what type of word it is and whether it describes a person, action, condition, or quality.
Suffix reference
| Word part | Meaning | Examples |
|---|---|---|
| -less | without; lacking | careless, harmless, hopeless |
| -ful | full of; having | helpful, careful, hopeful |
| -able / -ible | capable of; able to be | readable, visible, portable |
| -er / -or | person or thing performing an action | teacher, operator, investigator |
| -ist | person connected with a field or activity | scientist, artist, specialist |
| -tion / -sion | act; process; result | construction, decision, expansion |
| -ment | process; result; condition | development, improvement, agreement |
| -ous | having; full of | dangerous, cautious, famous |
| -ive | having the nature of; tending to | active, productive, destructive |
| -ize | to make; to become | modernize, organize, stabilize |
| -ity | state; quality; condition | clarity, stability, scarcity |
| -ness | state; condition; quality | kindness, darkness, weakness |
Example 1
Harmless most nearly means: A. causing severe injury | B. without danger or injury | C. difficult to understand | D. full of anger
Solution
- 1The suffix -less often means without.
- 2The root word is harm.
- 3Harmless means without harm.
Why: The suffix -less reverses the idea of harm by indicating its absence.
Example 2
Readable most nearly means: A. impossible to see | B. able to be read | C. written again | D. poorly written
Solution
- 1The suffix -able often means able to be or capable of.
- 2Readable means able to be read.
Why: Recognizing -able can reveal that a word describes something that can be done.
Example 3
Stability most nearly means: A. condition of being steady | B. sudden movement | C. failure to decide | D. act of destroying
Solution
- 1Stable means steady.
- 2The suffix -ity indicates a state, condition, or quality.
- 3Stability means the condition of being stable or steady.
Why: The suffix shows that the word describes a condition or quality rather than an action.
Section 3
Common Roots
A root carries the main idea of a word. Many English words contain roots from Latin or Greek. A small group of common roots can help with unfamiliar vocabulary, but roots are clues rather than complete definitions.
Root reference
| Word part | Meaning | Examples |
|---|---|---|
| bio | life | biology, biography |
| geo | earth | geography, geology |
| chron | time | chronological, chronology |
| therm | heat | thermal, thermometer |
| aqua | water | aquatic, aquarium |
| aud | hear | audible, audience |
| vis / vid | see | visible, vision, video |
| dict | say; speak | dictate, predict, contradict |
| scrib / script | write | describe, script, manuscript |
| port | carry | transport, portable, import, export |
| tract | pull; draw | attract, distract, extract |
| cred | believe; trust | credible, credulous, credentials |
| bene | good; well | benefit, benevolent |
| mal | bad; poor | malfunction, malice, malnutrition |
| rupt | break | rupture, interrupt, disrupt |
| struct | build | construct, structure, destruction |
| spect | look; see | inspect, spectator, respect |
| phon | sound | telephone, microphone, phonics |
Example 1
Credible most nearly means: A. believable | B. dangerous | C. temporary | D. silent
Solution
- 1The root cred relates to belief or trust.
- 2Credible likely means something that can be believed or trusted.
Why: Recognizing cred- points toward meanings involving belief or trust.
Example 2
Audible most nearly means: A. visible | B. able to be heard | C. difficult to carry | D. extremely bright
Solution
- 1The root aud relates to hearing.
- 2The suffix -ible means able to be.
- 3Audible means able to be heard.
Why: Both the root and suffix provide useful clues to the meaning.
Example 3
Disrupt most nearly means: A. restore order | B. interrupt normal activity | C. speak quietly | D. travel quickly
Solution
- 1The root rupt means break.
- 2The prefix dis- can suggest apart or away.
- 3The word suggests breaking apart normal order.
Why: The word parts suggest breaking or disturbing something that was continuing normally.
Section 4
Using Word Parts on Word Knowledge Questions
The goal is not to break apart every word. If you already know a word, use the meaning you know. Word parts are most useful when an unfamiliar word appears.
A practical process
1. Look at the whole word. 2. Check for a prefix. 3. Check for a suffix. 4. Look for a familiar root. 5. Form a rough meaning. 6. Compare it with the choices. 7. Eliminate choices that conflict with the clues.
For inaudible, in- suggests not, aud means hear, and -ible means able to be. Together they suggest not able to be heard. You need only enough information to select the closest answer.
Example 1
Portable most nearly means: A. able to be carried | B. impossible to break | C. extremely heavy | D. permanently attached
Solution
- 1Port relates to carry.
- 2-able means able to be.
- 3Together, the clues suggest able to be carried.
Why: The root and suffix point toward the same meaning.
Example 2
Benevolent most nearly means: A. kind | B. uncertain | C. noisy | D. temporary
Solution
- 1The root bene relates to good or well.
- 2Among the choices, kind is most closely connected with goodness toward others.
Why: Knowing bene- gives direction even though it does not provide the entire dictionary definition.
Example 3
Malfunction most nearly means: A. work incorrectly | B. improve gradually | C. speak clearly | D. move rapidly
Solution
- 1Mal- suggests bad or poor.
- 2Function means to work or operate.
- 3Malfunction means function badly or work incorrectly.
Why: The word part gives a strong clue while the rest tells what is being done badly.
Section 5
When Word Parts Can Mislead You
Prefixes, suffixes, and roots are useful, but they are not perfect. English contains words that changed meaning over time, and some words only look as if they contain a familiar root.
Use clues in the right order
Word parts should help narrow the answers, not replace knowing vocabulary. Recognizing re- as meaning again does not mean every word beginning with the letters re literally means again. Consider the complete word, meanings you already know, answer choices, and the sentence if one is provided.
The best priority is: known definition first; word-part clues second; context and elimination when needed.
Quick Review
Prefixes
- Prefixes appear at the beginning: un- not, re- again, pre- before, post- after, anti- against, sub- under/below, inter- between, intra- within, mis- wrong, dis- opposite/apart, bi- two, tri- three, multi- many.
Suffixes
- Suffixes appear at the end: -less without, -ful full of, -able/-ible able to be, -tion/-sion process or result, -ment condition/process/result, -ous having, -ize make/become, -ity/-ness state or quality.
Roots
- Roots carry the main idea: bio life, geo earth, chron time, therm heat, aqua water, aud hear, vis/vid see, dict speak, scrib/script write, port carry, tract pull, cred believe, bene good, mal bad, rupt break.
Best Strategy
- If you know the word, use its meaning. If you do not, look for familiar parts, form a rough meaning, compare choices, eliminate conflicts, and use context if available.