4.2 Latin & Greek Roots, Prefixes & Suffixes for Word Decoding

Key Takeaways

  • Over 60% of English academic, scientific, and technical vocabulary derives directly from Latin and Greek root morphemes.
  • Prefixes alter the core direction, negation, or intensity of a word (e.g., 'sub-' meaning under, 'un-' meaning not).
  • Suffixes primarily govern a word's part of speech (e.g., '-ous' forms adjectives, '-tion' forms nouns, '-ize' forms verbs).
  • Mastering 30 core roots unlocks the ability to decode over 1,000 complex, unfamiliar AFQT target words without rote memorization.
  • Systematic structural analysis (Prefix + Root + Suffix) allows test-takers to infer meaning and eliminate up to 75% of incorrect distractor choices.
Last updated: July 2026

4.2 Latin & Greek Roots, Prefixes & Suffixes for Word Decoding

When taking the CAT-ASVAB Word Knowledge subtest, you will inevitably encounter vocabulary words you have never seen or studied. Rather than guessing blindly, high-scoring candidates rely on morphological analysis—the process of breaking words down into their component units: prefixes, roots, and suffixes.

English is a hybrid language heavily built upon Latin and Greek roots. Understanding these foundational building blocks equips you with a structural decoder ring for higher-level AFQT vocabulary.

Word Meaning=Prefix (Direction/Negation)+Root (Core Semantic Anchor)+Suffix (Part of Speech)\text{Word Meaning} = \text{Prefix (Direction/Negation)} + \text{Root (Core Semantic Anchor)} + \text{Suffix (Part of Speech)}


Essential Latin & Greek Roots Master Reference

The root carries the primary semantic meaning of a word. Below is a comprehensive table of 20 high-frequency Latin and Greek roots frequently tested on the ASVAB.

Root MorphemeOriginCore MeaningTarget AFQT WordsSample Sentence Context
Bene / BonLatinGood, wellBenevolent, Beneficiary, BenignThe director was known for her benevolent leadership style.
Mal / MaleLatinBad, evil, illMalevolent, Malice, MalfunctionThe computer system suffered a severe malfunction.
ChronGreekTimeChronological, Anachronism, ChronicEvents were listed in strict chronological order.
CredLatinBelieve, trustCredible, Incredulous, CredentialThe witness provided a highly credible account of the event.
DictLatinSpeak, sayDictate, Contradict, VerdictThe evidence directly contradicted the suspect's claim.
Duc / DuctLatinLead, pullDeduct, Induce, ConductThe officer conducted a thorough briefing before takeoff.
Loq / LocLatinSpeak, talkLoquacious, Eloquent, InterlocutorThe spokesman gave an eloquent defense of the policy.
Path / PassGreek / LatinFeeling, sufferingApathy, Empathy, CompassionThe team showed complete apathy toward the minor rules.
PhilGreekLove, inclinationPhilanthropy, Philosophy, BibliophileThe general engaged in philanthropy after retirement.
Spect / SpecLatinLook, seeCircumspect, Spectator, InspectEngineers must inspect the hull for micro-fractures.
TractLatinPull, dragIntractable, Retract, DetractThe stubborn bolt proved completely intractable.
Vert / VersLatinTurnSubvert, Adverse, RevertAdverse weather conditions forced the unit to revert to plan B.
Voc / VokLatinVoice, callAdvocate, Revoke, EquivocateThe license was revoked following repeated safety infractions.
AutoGreekSelf, sameAutonomous, AutobiographyThe drone operated in fully autonomous mode.
Graph / GramGreekWrite, recordGraphic, Telegram, DiagramThe technician reviewed the wiring diagram carefully.
MorphGreekForm, shapeAmorphous, MetamorphosisCloud formations appeared amorphous over the valley.
PolyGreekMany, muchPolyglot, PolygonA polyglot interpreter was assigned to the coalition team.
TransLatinAcross, beyondTransient, Transitory, TransportThe transient rain storm passed quickly over the airfield.
OmniLatinAll, everyOmnipotent, Omniscient, OmnivorousThe radar system provided omnipresent coverage of the airspace.
VerLatinTrue, truthVeracity, Verify, VerdictIntelligence officers worked to verify the informant's claim.

Deconstructing Prefixes: Direction, Negation & Quantity

Prefixes attach to the beginning of root words to alter meaning, direction, or intensity. Identifying a prefix provides immediate context regarding whether a word implies addition, subtraction, opposition, or location.

Negation and Opposition Prefixes

  • A- / An- (Greek - without, lacking): Amorphous (without shape), Apathy (without feeling), Anarchy (without rule).
  • Anti- / Contra- / Counter- (Greek/Latin - against, opposite): Antipathy (feeling against), Contradict (speak against), Countermand (revoke an order).
  • Dis- / Un- / In- / Im- / Ir- / Il- (Latin/Germanic - not, opposite of): Disparate (not equal), Ineffable (not expressible), Impeccable (not flawed), Irrevocable (not retractable).

Directional and Spatial Prefixes

  • Ante- / Pre- (Latin - before): Antecedent (coming before), Precursor (forerunner).
  • Post- (Latin - after): Postscript (written after), Postpone (put after).
  • Sub- / Hypo- (Latin/Greek - under, below): Subterranean (underground), Hypodermic (under the skin).
  • Hyper- / Super- / Sur- (Greek/Latin - over, above, excessive): Hyperbole (over-statement), Superfluous (overflowing/extra).
  • Inter- (Latin - between, among): Intervene (come between), Intermittent (stopping and starting between times).
  • Intra- / Endo- (Latin/Greek - within, inside): Intramural (within walls), Endogenous (produced within).

Decoding Suffixes: Identifying Parts of Speech

Suffixes appear at the end of words. While prefixes alter meaning, suffixes primarily indicate the word's grammatical function.

Suffix CategoryCommon MorphemesGrammatical FunctionExamples
Adjective Suffixes-ous, -able, -ible, -ic, -ive, -ful, -antDescribes a noun; indicates quality or capabilityCapable, Lucrative, Placid, Resilient, Benevolent
Noun Suffixes-tion, -ity, -ment, -ance, -ence, -hood, -nessIdentifies a person, place, thing, or abstract stateDeference, Veracity, Apathy, Dictator, Malfunction
Verb Suffixes-ize, -ify, -ate, -enIndicates action or processElucidate, Curtail, Scrutinize, Verify, Vacillate

Step-by-Step Word Decoding Workflow on the CAT-ASVAB

When faced with an unfamiliar word on the exam, execute this 4-step decoding sequence:

  1. Strip Off Affixes: Separate the prefix and suffix from the core root.
    • Example Word: INDEFATIGABLE
    • Prefix: In- (Not)
    • Root: Fatigue (Tiredness / Exhaustion)
    • Suffix: -able (Capable of being)
  2. Synthesize Morpheme Meanings: Combine the isolated components.
    • Synthesis: "Not capable of being tired out."
  3. Match with Synonym Options: Select the option that aligns with your synthesized meaning.
    • Options: [A] Exhausted [B] Untiring [C] Weak [D] Lazy
    • Correct Selection: Untiring.
Test Your Knowledge

The Latin root LOQ / LOC means 'to speak'. Based on this root and morphological structure, what is the meaning of the word LOQUACIOUS?

A
B
C
D
Test Your Knowledge

Using your knowledge of prefixes and roots, what is the best definition of the target word CIRCUMSPECT?

A
B
C
D
Test Your Knowledge

The Greek root PATH relates to feelings or suffering. What does the word APATHY mean?

A
B
C
D