Study guide
4.2 Latin & Greek Roots, Prefixes & Suffixes for Word Decoding
Armed Forces Qualification Test AFQT
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1 Chapter 1: AFQT Structure, Scoring & Enlistment Requirements
1.1 AFQT Overview, Subtest Breakdown & CAT-ASVAB vs. P&P Format 1.2 The AFQT Scoring Formula (2×VE + AR + MK) & Percentile Norming 1.3 Branch Minimum Scores, AFQT Categories & Retake Policies
2 Chapter 2: Arithmetic Reasoning (AR) — Ratios, Rates & Percentages
2.1 Ratios, Proportions & Scale Conversions 2.2 Percentages, Discounts, Interest & Tax Calculations 2.3 Rate, Distance, Time & Speed Word Problems 2.4 Work Rates & Combined Labor Problems
3 Chapter 3: Arithmetic Reasoning (AR) — Mixtures, Sequences & Applied Math
3.1 Mixture, Concentration & Price-Blending Problems 3.2 Sequences, Patterns & Series Calculations 3.3 Averages, Weighted Averages & Statistical Word Problems
4 Chapter 4: Word Knowledge (WK) — Vocabulary & Word Structure
4.1 High-Frequency AFQT Vocabulary & Synonym Recognition 4.2 Latin & Greek Roots, Prefixes & Suffixes for Word Decoding 4.3 Context Clues & Words with Multiple Meanings
5 Chapter 5: Paragraph Comprehension (PC) — Reading Analysis & Inference
5.1 Identifying Main Ideas & Primary Purpose 5.2 Locating Supporting Details & Direct Facts 5.3 Drawing Logical Inferences & Implied Conclusions 5.4 Analyzing Tone, Author Perspective & Contextual Vocabulary
6 Chapter 6: Mathematics Knowledge (MK) — Fundamentals & Linear Algebra
6.1 Arithmetic Operations, Order of Operations & Number Properties 6.2 Exponents, Scientific Notation & Square Roots / Radicals 6.3 Linear Equations, Inequalities & Absolute Value 6.4 Systems of Linear Equations & Word-to-Algebra Translation
7 Chapter 7: Mathematics Knowledge (MK) — Advanced Algebra & Functions
7.1 Polynomial Operations & Factoring Techniques 7.2 Quadratic Equations, Factoring & Quadratic Formula 7.3 Coordinate Geometry: Slope, Distance, Midpoint & Linear Graphs
8 Chapter 8: Mathematics Knowledge (MK) — Geometry & Spatial Math
8.1 Angles, Triangles & Pythagorean Theorem 8.2 Quadrilaterals, Polygons & Circle Geometry 8.3 3D Geometry: Surface Area & Volume of Solids 8.4 Basic Geometric Transformations & Trigonometric Ratios
4.2 Latin & Greek Roots, Prefixes & Suffixes for Word Decoding
Key Takeaways Explain This Topic AI
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)} Word Meaning = Prefix (Direction/Negation) + Root (Core Semantic Anchor) + 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 Morpheme Origin Core Meaning Target AFQT Words Sample Sentence Context
Bene / Bon Latin Good, well Benevolent, Beneficiary, Benign The director was known for her benevolent leadership style.
Mal / Male Latin Bad, evil, ill Malevolent, Malice, Malfunction The computer system suffered a severe malfunction .
Chron Greek Time Chronological, Anachronism, Chronic Events were listed in strict chronological order.
Cred Latin Believe, trust Credible, Incredulous, Credential The witness provided a highly credible account of the event.
Dict Latin Speak, say Dictate, Contradict, Verdict The evidence directly contradicted the suspect's claim.
Duc / Duct Latin Lead, pull Deduct, Induce, Conduct The officer conducted a thorough briefing before takeoff.
Loq / Loc Latin Speak, talk Loquacious, Eloquent, Interlocutor The spokesman gave an eloquent defense of the policy.
Path / Pass Greek / Latin Feeling, suffering Apathy, Empathy, Compassion The team showed complete apathy toward the minor rules.
Phil Greek Love, inclination Philanthropy, Philosophy, Bibliophile The general engaged in philanthropy after retirement.
Spect / Spec Latin Look, see Circumspect, Spectator, Inspect Engineers must inspect the hull for micro-fractures.
Tract Latin Pull, drag Intractable, Retract, Detract The stubborn bolt proved completely intractable .
Vert / Vers Latin Turn Subvert, Adverse, Revert Adverse weather conditions forced the unit to revert to plan B.
Voc / Vok Latin Voice, call Advocate, Revoke, Equivocate The license was revoked following repeated safety infractions.
Auto Greek Self, same Autonomous, Autobiography The drone operated in fully autonomous mode.
Graph / Gram Greek Write, record Graphic, Telegram, Diagram The technician reviewed the wiring diagram carefully.
Morph Greek Form, shape Amorphous, Metamorphosis Cloud formations appeared amorphous over the valley.
Poly Greek Many, much Polyglot, Polygon A polyglot interpreter was assigned to the coalition team.
Trans Latin Across, beyond Transient, Transitory, Transport The transient rain storm passed quickly over the airfield.
Omni Latin All, every Omnipotent, Omniscient, Omnivorous The radar system provided omnipresent coverage of the airspace.
Ver Latin True, truth Veracity, Verify, Verdict Intelligence 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 Category Common Morphemes Grammatical Function Examples
Adjective Suffixes -ous, -able, -ible, -ic, -ive, -ful, -ant Describes a noun; indicates quality or capability Capable, Lucrative, Placid, Resilient, Benevolent
Noun Suffixes -tion, -ity, -ment, -ance, -ence, -hood, -ness Identifies a person, place, thing, or abstract state Deference, Veracity, Apathy, Dictator, Malfunction
Verb Suffixes -ize, -ify, -ate, -en Indicates action or process Elucidate, 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:
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)
Synthesize Morpheme Meanings: Combine the isolated components.
Synthesis: "Not capable of being tired out."
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 .