Roots, Prefixes and Suffixes

🔤 Roots, Prefixes and Suffixes

Part 1 of 7 — How Word Parts Unlock Meaning

Topic Overview

Why Word Parts Matter on Word Knowledge

Word Knowledge (WK) gives you 15 questions in 9 minutes on the CAT-ASVAB, about 36 seconds each. Many questions show a word alone, with no sentence to help: "Malfunction most nearly means ___." When there is no context, the word itself is the only clue you have.

That is where word parts come in. Most longer English words are built from smaller pieces borrowed from Latin and Greek. A few dozen of those pieces show up in thousands of words. Learn the pieces once and you can take apart words you have never seen.

And WK is worth the effort. Your AFQT sum is AR + MK + 2 × VE, where VE is a weighted blend of Word Knowledge and Paragraph Comprehension (WK counting more). Verbal skill is half of the AFQT sum.

The Three Kinds of Parts

A word can have more than one prefix or suffix, and some words are just a root plus a suffix.

Taking Words Apart

Example 1: unpredictable

Put it back together: not able to be said beforehand. In plain words, unpredictable means impossible to know in advance, changing without warning.

Example 2: transport

Transport means to carry across, from one place to another. The same root shows up in portable (can be carried), export (carry out of a country) and import (carry in).

The Big Idea: Word Families

One root opens a whole family of words. Once you know that port means carry, every member of the family gives up its meaning. The goal of this lesson is not to memorize lists of words, but to learn the families.

Key Fact: Word parts give you a direction, not always an exact dictionary definition. Use them to rule out choices that point the wrong way, then pick the choice that fits best.

A Three-Step Routine for a Word-Alone Question

1. Split the word into parts you recognize.
2. Translate each part and build a rough meaning.
3. Match the rough meaning to the closest choice, and eliminate choices that point the opposite way.

Warm-up. 🎯 Split, translate, match.

Key Takeaways — Part 1

• Word-alone WK questions give you no context; word parts become your clue
• Prefix (front) changes meaning; root (core) carries meaning; suffix (end) sets the part of speech
• Learn families: one root, many words (port: transport, portable, export, import)
• Parts give a direction: split → translate → match, and eliminate choices that point the wrong way

Up Next: Part 2 — the prefixes that flip, place and time a word's meaning.

🔤 Roots, Prefixes and Suffixes

Part 2 of 7 — Prefixes That Change Meaning

Prefixes That Mean "Not" or "Against"

These are the most valuable prefixes on the test, because they flip a word. If you know the base word, the prefix hands you the opposite.

Spelling note: in- changes to im- before b, m and p (impolite), to il- before l (illegal) and to ir- before r (irregular). All four mean the same thing.

Prefixes of Time and Place

Key Fact: A prefix on a word you know gives you the answer almost for free. Un- + steady = not steady. Look for a familiar word hiding behind the prefix.

Worked Examples

Example 1: illegible

• Split: il + leg + ible.
• Translate: not + read + able to be.
• Build: not able to be read.
• So: illegible handwriting is too messy to read. A choice like unreadable matches; misspelled is a trap (misspelled words can still be read).

Example 2: postpone

• Split: post + pone.
• Translate: after + put (the same root as position).
• Build: put until after.
• So: to postpone is to put off until later, delay. The opposite, move up or rush, is the trap.

Example 3: submerge

• Split: sub + merge.
• Translate: under + dip (as in emerge, to come out of the water).
• Build: put under.
• So: to submerge is to put or go under water. A submarine is a ship that goes under the sea.

When You Do Not Know the Root

You do not need every piece. In submerge, knowing only that sub- means under is enough to choose sink over float, rise or spray. One known part can eliminate two or three choices.

Use the prefix. 🎯 Pick the choice closest in meaning to the bold word.

Prefix meanings. 🔽

Sentence A. The first transatlantic flight without a stop took place in 1919.

Sentence B. Rather than climb the steep ridge, the patrol chose to circumvent it by following the river.

Count the prefixes. ✍️

Look at these six words:

unsteady · impolite · interstate · irregular · prewar · exhale

1) How many of the six words begin with a prefix that means not?

2) How many begin with a prefix that means before?

3) How many begin with a prefix that means out?

Key Takeaways — Part 2

• "Not" prefixes flip a word: un-, in-/im-/il-/ir-, dis-, non-; mis- = wrongly; anti-/contra-/counter- = against; mal- = bad
• Time and place prefixes: pre- before, post- after, re- again/back, sub- under, super- over, inter- between, trans- across, ex- out, circum- around, de- down/undo
• Look for a familiar word behind the prefix
• Even one known part can eliminate two or three choices

Up Next: Part 3 — the Latin roots that sit at the core of hundreds of test words.

🔤 Roots, Prefixes and Suffixes

Part 3 of 7 — Latin Roots

The Core of the Word

The root carries the main meaning. Latin roots are the backbone of formal English, the kind of words that show up in regulations, news reports and the ASVAB. Here are the families worth knowing cold:

Key Fact: You already know at least one word in almost every family: tractor (pulls), eject (throws out), erupt (breaks out). Use the word you know to unlock the word you don't.

Worked Examples

Example 1: retrospect

• Split: retro + spect.
• Translate: back + look.
• So: retrospect is looking back on the past. "In retrospect, we should have left earlier" means looking back now.

Example 2: interject

• Split: inter + ject.
• Translate: between + throw.
• So: to interject is to throw a remark in between, to interrupt with a comment. "During the briefing, the pilot interjected a question about fuel."

Example 3: abrupt

• Split: ab + rupt.
• Translate: away + break.
• So: abrupt means breaking off suddenly: an abrupt stop, an abrupt change in the weather. A choice like sudden fits; gradual is the opposite trap.

Combine Prefix and Root

The real power comes from stacking what you learned in Part 2 with what you learn here:

Use the root. 🎯 Pick the choice closest in meaning to the bold word.

Root to meaning. 🔽

Sentence A. The clerk will transcribe the recorded interview so that the investigators have a written copy.

Sentence B. In the training scenario, the role players tried to abduct the convoy's interpreter.

Find the shared root. ✍️ Type the root exactly as it appears in all three words.

1) predict · verdict · dictate

2) traction · distract · extract

Key Takeaways — Part 3

• Latin roots carry the core meaning: port carry, dict say, spect look, scrib/script write, duc/duct lead, ject throw, rupt break, vert/vers turn, ced/cess go, mit/miss send, tract pull, voc/vok call, cred believe, fid trust, aud hear, vid/vis see, bene/mal good/bad
• Use a word you already know (tractor, eject, erupt) to unlock the family
• Stack prefix + root: ex + tract = pull out; re + cede = go back

Up Next: Part 4 — Greek roots and the number parts that tell you how many.

🔤 Roots, Prefixes and Suffixes

Part 4 of 7 — Greek Roots and Number Parts

Greek Roots

Greek roots fill the vocabulary of science, medicine and technology. Many of them are already in words you use every day.

Number Parts

Key Fact: Many Greek words are two roots glued together: tele + scope (far + look), auto + graph (self + write), geo + logy (earth + study). Translate each half and the meaning appears.

Worked Examples

Example 1: chronological

• Split: chron + o + log + ical.
• Translate: time + study/word + (describing word).
• So: chronological means arranged in the order of time. A chronological list of your jobs starts with the earliest one.

Example 2: empathy

• Split: em + path + y.
• Translate: in + feeling + (noun).
• So: empathy is feeling what another person feels, putting yourself in their place. Its cousin sympathy (syn = with) is feeling for someone.

Example 3: bilingual

• Split: bi + lingu + al.
• Translate: two + tongue/language + (describing word).
• So: a bilingual soldier speaks two languages. The number part does most of the work: multilingual would be many languages.

Watch Out for "Half Meanings"

Some roots have two senses. Path means feeling (sympathy) and disease (pathology, the study of disease). Log means word (dialogue) and study (biology). Use the rest of the word to decide which sense fits.

Use the Greek root. 🎯 Pick the choice closest in meaning to the bold word.

Build the meaning. 🔽

Sentence A. Soldiers in the cold-weather course learn to spot the early signs of hypothermia.

Sentence B. The new drone is autonomous; it can fly its whole route with no pilot at the controls.

Number parts. ✍️ Type a number for each.

1) A trilogy is a series of how many books or movies?

2) A bicentennial celebrates an anniversary of how many years?

3) A decade is how many years?

Key Takeaways — Part 4

• Greek roots: bio life, graph write, phon sound, chron time, path feeling/disease, phil love, log/logy word/study, auto self, tele far, micro small, therm heat, hydr water, geo earth, dem people, onym name, scope look
• Number parts: mono/uni 1, bi/di 2, tri 3, quad/tetra 4, dec 10, cent 100, multi/poly many, semi/hemi half
• Many Greek words are two roots glued together: translate both halves
• Some roots have two senses (path, log): let the rest of the word decide

Up Next: Part 5 — suffixes, the endings that tell you a word's part of speech.

🔤 Roots, Prefixes and Suffixes

Part 5 of 7 — Suffixes and Parts of Speech

What a Suffix Tells You

A suffix sits at the end of a word and usually tells you its part of speech: is it a thing (noun), an action (verb) or a description (adjective)? That matters on Word Knowledge because the right answer is always the same part of speech as the test word. A noun's synonym is a noun; an action's synonym is an action.

Suffixes That Add Meaning

A few suffixes do more than set the part of speech:

Key Fact: Check the ending of the test word and the endings of the choices. A choice in the wrong part of speech can be eliminated even if you have no idea what the word means.

Worked Examples

Example 1: relentless

• Split: relent + less.
• Translate: give in, ease up + without.
• So: relentless means without easing up: a relentless storm, a relentless training schedule. Persistent and nonstop are good matches.

Example 2: pacify

• Split: pac + ify.
• Translate: peace (as in Pacific, the "peaceful" ocean) + make.
• So: to pacify is to make peaceful, to calm someone down. The suffix -ify tells you the answer must be a verb: calm, soothe.

Example 3: perilous

• Split: peril + ous.
• Translate: danger + full of.
• So: perilous means full of danger. If the choices were dangerous · danger · endanger · dangerously, only dangerous is an adjective like perilous. The others are a noun, a verb and an adverb.

Use Part of Speech to Eliminate

Suppose the test word is fortitude (a noun, from fort = strong) and the choices are brave · courage · strengthen · boldly. Even before you think about meaning, only courage is a noun. Brave is an adjective, strengthen is a verb, boldly is an adverb. Fortitude means courage and strength of mind.

Use the suffix. 🎯 Pick the choice closest in meaning to the bold word.

Name the part of speech from the suffix. 🔽

Sort by suffix. ✍️

courageous · modernize · novelist · visible · careless · motion

1) How many of the six words are adjectives (describing words)?

2) How many are verbs?

3) How many are nouns?

Key Takeaways — Part 5

• Suffixes set the part of speech: nouns (-tion, -ment, -ity, -ness, -ance, -er, -ist), verbs (-ize, -ify, -ate, -en), adjectives (-ous, -ive, -able, -ful, -less, -al, -ic), adverbs (-ly)
• Some suffixes add meaning: -less without, -ful full of, -able can be, -ous full of, -ify/-ize to make
• The correct answer is always the same part of speech as the test word: use that to eliminate

Up Next: Part 6 — the traps: words that only look like they contain a root, and how to use parts without overtrusting them.

🔤 Roots, Prefixes and Suffixes

Part 6 of 7 — Test Strategy and Common Traps

Word Parts on the Clock

You have about 36 seconds per Word Knowledge question on the CAT-ASVAB (15 questions in 9 minutes). Word parts are fast when you use them as a shortcut, not as a research project.

You cannot return to an answered question on the CAT, and you must answer to move on. Unanswered questions at the time limit are scored as random guesses, and a run of wrong answers at the very end of a subtest carries a relatively large penalty, so do not get stuck dissecting one word.

Trap 1: The Prefix That Is Not "Not"

In- usually means not, but it can also mean in or into:

And a few words are famous for fooling people:

• Inflammable means easily set on fire, the same as flammable. (The in- here means into, as in bursting into flame.) A truck marked INFLAMMABLE is dangerous, not safe.
• Invaluable means priceless, so valuable it cannot be measured, not "worthless."
• Infamous means famous for something bad, not "unknown."

Trap 2: Letters That Only Look Like a Root

Not every "port" is a root. Portion (a share) and portrait (a picture of a person) have nothing to do with carrying. Pressure contains pre, but it does not mean "before." If a split gives you nonsense, drop it and use another strategy.

Trap 3: Trusting a Root Too Far

A root gives a direction, not a definition. Submarine and substantial both start with sub, but substantial means large or considerable, nothing to do with being under anything. Use the root to rule out choices that point the wrong way, then choose the best fit among what is left.

Worked Examples

Example 1: the "in-" that means "into"

Inflammable most nearly means: fireproof · burnable · harmless · invisible

• If you read in- as not, you would pick "fireproof," the trap.
• Inflammable shares its root with inflame and flame: it means able to burst into flame.
• Answer: burnable.

Example 2: the "in-" that intensifies

Invaluable most nearly means: worthless · priceless · cheap · ordinary

• Reading in- as not gives "not valuable," so "worthless," the trap.
• Invaluable means too valuable to put a price on.
• Answer: priceless.

Example 3: the "in-" that turns famous bad

Infamous most nearly means: unknown · notorious · humble · lucky

• "Not famous" would give "unknown," the trap.
• An infamous outlaw is well known for being bad.
• Answer: notorious.

How to Protect Yourself

1. If the split gives a meaning that sounds strange, doubt it.
2. Ask whether you have heard the word in real life (a warning sign, a news story).
3. Use part of speech and elimination to back up the root.

Avoid the traps. 🎯 Pick the choice closest in meaning to the bold word.

Which "in-"? 🔽 Decide what the prefix means in each word.

Key Takeaways — Part 6

• Budget about 36 seconds: know it → split it → eliminate → choose; you cannot skip or go back
• In- can mean not or in/into: inflammable = burnable, invaluable = priceless, infamous = famous for something bad, inhabit = live in
• Some letters only look like a root (portion, portrait, pressure, restive)
• A root gives a direction, not a definition; back it up with part of speech, real-life memory and elimination

Up Next: Part 7 — a mixed mastery set using every kind of word part.

🔤 Roots, Prefixes and Suffixes

Part 7 of 7 — Mixed Mastery Set

How to Use This Set

Eleven questions that mix every kind of word part, in both Word Knowledge formats. Work them at test speed: about 36 seconds each, so roughly 6 to 7 minutes for the set.

For each word:

1. Know it? Answer and move on.
2. Split it into prefix, root and suffix.
3. Translate and build a rough meaning.
4. Eliminate choices that point the wrong way or are the wrong part of speech.
5. Watch the traps: in- meaning into, letters that only look like a root, look-alike words.

Quick Reference

Mastery set, questions 1–6. 🎯

Mastery set, questions 7–11. 🎯

Key Takeaways — Roots, Prefixes and Suffixes

• Split → translate → match → eliminate, in about 36 seconds
• Prefixes flip or place meaning; roots carry it; suffixes set the part of speech
• Learn families, not lists: one root unlocks dozens of words
• The answer is always the same part of speech as the test word
• Watch the traps: in- that means into (inflammable, inhabit), letters that only look like roots, look-alike words (enervate, deduce/deduct)

Next steps: take the exit quiz for this topic, then move on to Synonyms, Connotation and Test Strategy for the word-alone questions where no part or clue helps.