Word Knowledge
The Word Knowledge subtest measures vocabulary. Every question has the same two shapes: either an underlined word in a short sentence, or a single word with no context. You pick the answer choice closest in meaning. You are never asked for the dictionary definition — only the best of the four choices, even if none is a perfect match.
Vocabulary-Building Strategies
The fastest gains come from a small set of habits practiced daily for two to four weeks before the test.
Read above your comfort level. Newspaper editorials, Scientific American, The Atlantic, military doctrine publications, and SAT/GRE word lists all expose you to words you would never meet in casual conversation. Pace matters less than variety.
Keep a "new word" log. Whenever a word stops you, write down: 1. The word. 2. The sentence where you found it. 3. A one-line definition in your own words. 4. A synonym you already know.
Active recall — covering the definition and trying to produce it — beats passive re-reading by a wide margin.
Use spaced repetition. Review yesterday's words today, last week's words this week, last month's words this month. Flashcard apps like Anki and Quizlet schedule this automatically. Ten minutes a day across two weeks adds roughly 100–200 durable words.
Learn words in families, not in isolation. Once you know benevolent, you almost have benefactor, beneficial, benediction, and benign for free. The roots and prefixes section below is the lever for this.
Practice on real test items. Free practice banks in Kaplan, Peterson's, Mometrix, and the official DoD CEP materials use the same sentence-stem style. Familiarity with the format is half the speed advantage on test day.
Process-of-elimination is a real strategy. When the target word is unfamiliar: 1. Cross out answer choices you know are wrong. 2. Mark choices that have a different connotation (positive vs. negative) than the target. Words that feel praising rarely match words that feel critical. 3. Pick the closest survivor and move on. The test is timed; do not burn two minutes on one unknown.
Pace. The paper test gives roughly 11 minutes for 35 questions; the CAT-ASVAB version gives roughly 8 minutes for 16. Either way, that is under 20 seconds per item. Train at that pace.
Roots, Prefixes, and Suffixes
English borrows heavily from Latin and Greek. Learning a few hundred roots unlocks thousands of words.
Common prefixes (front of the word)
| Prefix | Meaning | Example |
|---|---|---|
| a-, an- | not, without | amoral, anonymous |
| anti- | against | antibiotic, antithesis |
| auto- | self | autograph, autonomous |
| bene- | good, well | benefit, benevolent |
| bi- | two | bicycle, bilateral |
| circum- | around | circumvent, circumference |
| co-, con-, com- | with, together | coexist, converge, compose |
| contra-, counter- | against | contradict, counterattack |
| de- | down, away, reverse | descend, deactivate |
| dis- | not, apart | disagree, disperse |
| ex- | out, former | exit, exhale |
| extra- | beyond | extraordinary, extracurricular |
| hyper- | over, excessive | hyperactive |
| hypo- | under, below | hypothermia |
| in-, im-, il-, ir- | not | invisible, impossible, illegal, irregular |
| inter- | between | interstate, intervene |
| intra- | within | intramural |
| mal- | bad, ill | malicious, malady |
| micro- | small | microscope |
| mis- | wrong, badly | misjudge, misplace |
| mono- | one | monotone, monopoly |
| multi- | many | multitude, multilingual |
| neo- | new | neonatal |
| non- | not | nonfiction |
| omni- | all | omnipotent, omnivore |
| pan- | all | pandemic |
| post- | after | postpone, postwar |
| pre- | before | preview, prevent |
| pro- | forward, for | progress, propel |
| re- | again, back | reread, return |
| semi- | half | semicircle |
| sub- | under | submarine, subordinate |
| super- | above, beyond | supervise, supersonic |
| trans- | across | transport, translate |
| un- | not, reverse | unable, unfold |
Common roots (heart of the word)
| Root | Meaning | Example |
|---|---|---|
| aud | hear | audible, auditorium |
| bio | life | biology, biography |
| chron | time | chronological, synchronize |
| cred | believe | credible, incredible |
| dict | speak, say | dictate, contradict |
| duc, duct | lead | conduct, induce |
| fac, fact, fect | make, do | factory, manufacture, defect |
| graph, gram | write, drawing | autograph, diagram |
| ject | throw | eject, project |
| log, logy | word, study of | dialogue, biology |
| man, manu | hand | manual, manufacture |
| mit, miss | send | transmit, dismiss |
| path | feeling, suffering | sympathy, pathology |
| phon | sound | telephone, symphony |
| port | carry | transport, portable |
| scrib, script | write | describe, transcript |
| sens, sent | feel | sensitive, consent |
| spec, spect | look, see | inspect, spectator |
| ten, tain | hold | tenant, contain |
| tract | pull, drag | attract, retract |
| vert, vers | turn | invert, reverse |
| vid, vis | see | video, visible |
| voc | voice, call | vocal, advocate |
Common suffixes (end of the word — usually signals part of speech)
| Suffix | Indicates | Example |
|---|---|---|
| -able, -ible | capable of | readable, flexible |
| -al | relating to | natural |
| -ance, -ence | state of | importance, patience |
| -ation, -tion | action or result | creation |
| -ed | past tense | walked |
| -er, -or | one who | teacher, actor |
| -ful | full of | hopeful |
| -ic | relating to | poetic |
| -ify | to make | clarify |
| -ism | belief, condition | capitalism |
| -ist | one who practices | artist |
| -ity | quality of | purity |
| -ize | to make | modernize |
| -less | without | fearless |
| -ly | in a manner (adverb) | quickly |
| -ment | action or result | movement |
| -ness | state of | kindness |
| -ous | full of | dangerous |
| -tion | action of | invention |
Putting roots together. Benevolent = bene- (good) + vol- (will, wish) + -ent (adj.) = "well-wishing." Circumspect = circum- (around) + spec- (look) = "looking around carefully" — cautious. Even if you have never seen the word, decoding it leaves only one or two plausible answer choices.
Synonyms vs. Antonyms
A synonym is a word with the same or nearly the same meaning. Big / large. Fast / quick. Begin / commence. Word Knowledge is fundamentally a synonym-matching task: the right answer is the choice closest to the target word in meaning.
An antonym is a word with the opposite meaning. Hot / cold. Open / close. Generous / stingy. The test rarely asks for antonyms — but watch out for them as trap distractors. If the target word is abundant (plentiful), the choice scarce will be sitting in the answer list to catch students who skim.
Connotation matters. Two technical synonyms can feel very different. - Childlike (innocent, charming) vs. childish (immature, petty). - Confident (positive) vs. arrogant (negative). - Thrifty (positive) vs. cheap (negative). - Slender (positive) vs. scrawny (negative).
When two answer choices are near-synonyms of the target, the one with the matching positive-or-negative tilt is usually correct.
Register matters. Words live in different registers — formal, neutral, casual, slang. - Inebriated (formal) — drunk (neutral) — hammered (slang). - Reside (formal) — live (neutral) — crash (slang).
ASVAB answers stay in formal/neutral register. A slang choice is almost always wrong.
False synonyms to watch. English is full of words that look alike but mean different things — commonly confused pairs:
| Pair | Quick distinction |
|---|---|
| accept / except | receive / leave out |
| affect / effect | (usually) verb / noun |
| allusion / illusion | reference / false image |
| complement / compliment | complete / praise |
| discreet / discrete | private / separate |
| eminent / imminent | distinguished / about to happen |
| farther / further | physical distance / metaphorical |
| imply / infer | speaker hints / listener concludes |
| principle / principal | rule / leader (or main) |
| stationary / stationery | not moving / paper goods |
These pairs are favorite test material. When a question hinges on one of them, slow down and read the sentence's intended sense.
The four-choice contrast pattern. A common item gives the target word and four choices that span the meaning space: one true synonym, one antonym, one unrelated word, and one near-synonym in the wrong direction. Eliminating the antonym and the unrelated word usually leaves two candidates that differ in connotation or register — pick the better match.
Context-Clue Method
About half of all Word Knowledge questions place the target word in a short sentence. The sentence is your single biggest advantage. Even when the word is unknown, the sentence almost always leaks its meaning if you read deliberately.
The four kinds of context clue:
- Definition clue. The sentence states the meaning directly.
- The doctor performed an arthroscopy, an examination of the joint using a small camera.
-
The phrase after the comma defines arthroscopy outright.
-
Synonym (restatement) clue. A nearby word means roughly the same thing.
- The sergeant's terse instructions, brief and to the point, left no room for questions.
-
Brief and to the point tells you terse means short and direct.
-
Antonym (contrast) clue. A nearby word means the opposite, often signaled by but, however, although, on the other hand, unlike, instead of.
- Although she expected the road to be smooth, she found it riddled with potholes.
-
The contrast with smooth tells you riddled with potholes means rough/full of holes.
-
Inference clue. No single word gives it away — but the situation does. You reason from what is plausible.
- After three nights of poor sleep, his usually sharp judgment had become muddled.
- From the cause (poor sleep) you infer muddled means confused or unclear.
A four-step routine for context items:
- Cover the answer choices first. Read the sentence and predict your own word for the blank or underlined target. If your prediction is "started," then commenced, initiated, began all match — you have already narrowed down to the right family.
- Now reveal the choices and find the one closest to your prediction. If two choices match, return to the sentence and reread for tone or precision.
- Substitute the candidate back into the sentence. A correct answer should not sound awkward and should preserve the original meaning. If it changes the sentence's sense, it is wrong.
- Eliminate clear opposites. Mark and discard antonyms of your prediction immediately.
Watch the signal words. They cue the relationship between parts of the sentence: - Continuation / similarity: and, also, moreover, furthermore, similarly, likewise. The next phrase usually agrees with the previous one. - Contrast: but, however, yet, although, despite, on the contrary, whereas, while. The next phrase usually flips direction. - Cause / effect: because, since, therefore, thus, so, as a result. Effects often define their causes. - Example: for example, such as, including. The example illustrates the meaning of an earlier abstract word.
Worked example. The mountaineer's tenacity, his refusal to give up despite frostbite and exhaustion, finally got him to the summit. - Predict your own word: determination, stubbornness, persistence. - Tenacity must mean refusal to give up — confirmed by the appositive. - Among the choices, persistence matches; fatigue (an antonym situation), skill, and fear are all wrong.
When the sentence does not help. A small fraction of items give context too thin to use (The argument was specious.). In that case, fall back on roots: spec- (look, see) + -ious — looking good on the surface — false but plausible. Then pick the closest survivor and move on.