Root Words
Latin and Greek roots are the core of most hard ASVAB vocabulary, learn 25 roots and unlock hundreds of words.
Formula Reference
- Latin root 'port' (carry): transport, portable, import, export, porter
- Latin root 'rupt' (break): disrupt, interrupt, rupture, erupt, corrupt
- Latin root 'duc/duct' (lead): conduct, deduce, introduce, induce, duct
- Greek root 'chron' (time): chronological, synchronize, anachronism, chronic
- Greek root 'bio' (life): biology, biography, antibiotic, microbiology
- Latin root 'bene' (good): benefit, benevolent, beneficial, benign
The case for learning roots
There are roughly 400,000 words in standard English dictionaries. You cannot memorize them all. But about 60–70% of common English words have Latin or Greek roots, and those roots cluster into patterns. Learn the pattern, recognize the word.
This guide covers the roots that pay off most on the ASVAB. Pair it with the Prefixes & Suffixes guide for maximum range.
High-payoff Latin roots
| Root | Meaning | Example words |
|---|---|---|
| port | carry | transport, import, portable |
| rupt | break | disrupt, erupt, corrupt |
| duc/duct | lead | conduct, deduce, introduction |
| scrib/script | write | describe, prescription, manuscript |
| vis/vid | see | visible, vision, evident |
| dict | say | dictate, predict, contradict |
| fac/fact | make/do | factory, manufacture, factor |
| mit/miss | send | transmit, mission, dismiss |
| vert/vers | turn | convert, divert, version |
| cap/cept | take/seize | capture, intercept, accept |
High-payoff Greek roots
| Root | Meaning | Example words |
|---|---|---|
| chron | time | chronological, synchronize |
| bio | life | biology, biography, antibiotic |
| graph | write | paragraph, photograph, autograph |
| phon | sound | telephone, microphone, symphony |
| geo | earth | geography, geology, geothermal |
| psych | mind | psychology, psyche, psychiatric |
| therm | heat | thermometer, thermal, hypothermia |
| scope | view/watch | telescope, microscope, periscope |
How to use roots on test day
When you see an unfamiliar word, do this fast breakdown:
- Can you spot a root? Underline it mentally.
- Is there a prefix that reverses or modifies it?
- Does the suffix tell you part of speech?
Example: circumspect, circum (around) + spect (look). To look around before acting, cautious, careful.
Example: benefactor, bene (good) + fac (make/do) + -or (one who). One who does good, a patron or donor.
You may not get the exact dictionary definition, but you get close enough to eliminate two or three wrong answers. That's all you need.
Four word families to drill first
Vision words, visible, invisible, envision, visual, visualize, vision, revision (all from vis)
Time words, chronic, chronological, synchronize, anachronism, chronicle (all from chron)
Life words, biology, biography, biome, antibiotic, symbiosis (all from bio)
Sound words, telephone, symphony, microphone, phonics, euphony (all from phon)
Learn one family per study session. By the time you sit the test, these roots will fire automatically.
Common Pitfalls
- ⚠Treating roots as perfect definitions, roots give a direction, not a dictionary entry
- ⚠Confusing roots that look similar: 'ped' (foot, Latin: pedal) vs. 'ped' (child, Greek: pediatric), check the full word
- ⚠Forgetting that a root often changes spelling when combined: 'duc' becomes 'duct' or 'duce'
- ⚠Relying on root alone without the prefix, 'benign' vs. 'malign' flip meaning entirely with prefix
Worked Examples
Q1: CHRONIC most nearly means: (A) sudden (B) long-lasting (C) painful (D) contagious
Answer: Chron = time. Chronic = persisting over a long period of time. Answer: B
Q2: POROUS most nearly means: (A) heavy (B) full of small holes (C) smooth (D) tightly sealed
Answer: Porous derives from 'pore' (opening/passage). A porous material has many small openings, it allows passage. Answer: B
Q3: MAGNANIMOUS most nearly means: (A) powerful (B) large (C) generous in spirit (D) easily angered
Answer: Magnus = great. Animus = spirit/mind. Magnanimous = great-spirited, generous, forgiving. Answer: C