GRE and TOEFL Vocabulary: Learn Words by Root Family

The fastest way to organize GRE and TOEFL vocabulary is to learn words in root families rather than as an alphabetical list. A family is a Latin or Greek root plus the words built on it: loqu (speak) gives you eloquent, loquacious, colloquial, soliloquy and circumlocution. Once one member is secure, the others have something to attach to, and when an unfamiliar word appears in a passage you have a sensible first guess about its meaning.

This page is a working reference. It lists fourteen families that feed a lot of formal, academic English, gives the exam-level members of each with short definitions, and flags the cases where the root misleads. At the end there is a method for turning the families into daily practice.

Why root families suit these two exams

The GRE tests vocabulary most directly in Text Completion and Sentence Equivalence questions. Both reward fine distinctions: you need to know not just that laconic has something to do with speech, but that it means using few words, so that it fits a sentence about a terse manager and not one about a rambling lecturer. Sentence Equivalence also asks you to find two answers that produce sentences with the same meaning, so knowing clusters of related words is directly useful.

The TOEFL leans on academic reading and lectures. You meet formal words in context and have limited time to work them out. A root will not hand you a definition, but it narrows the options. If you know chron means time, anachronism is much less mysterious.

Root families also help your memory in a plainer way. Studying credible, credulous, incredulous and credence together forces you to notice the differences between them, and those differences are exactly what exam questions probe.

How to read the families below

Each section gives the root, its original meaning, and a set of words that are common in academic writing or on exam word lists. Definitions are short and practical. Where a word's meaning drifted away from the root, that is noted. The goal is not to memorize the etymology but to use it as a hook.

spec, spic: to look

• circumspect: cautious; careful to consider all circumstances before acting (literally "looking around").
• introspection: examining your own thoughts and feelings.
• perspicacious: having keen insight; quick to notice and understand.
• conspicuous: easy to notice; standing out.
• retrospect: a look back at past events, usually in the phrase in retrospect.
• specious: seeming plausible or attractive on the surface but actually wrong or misleading.

Specious is the one to watch. It comes from a Latin word for appearance, so the "look" idea is really "looks right but is not". A specious argument is a bad argument dressed up to look good.

dict, dic: to say

• edict: an official order issued by an authority.
• verdict: a decision or judgment, originally "truly said".
• indict: to formally charge with a crime (pronounced in-DITE).
• dictum: a formal pronouncement or a short statement of a principle.
• valedictory: serving as a farewell, as in a valedictory speech.
• benediction and malediction: a blessing and a curse.
• contradict: to say the opposite of.

Indict catches many learners out in speaking, because the c is silent. It is a good word to practice aloud.

port: to carry

• comport: to behave in a particular way (comport oneself with dignity); the noun is comportment.
• deport: to expel from a country; deportment means a person's bearing or manners.
• purport: to claim or appear to be something, often falsely (a letter purporting to be from the bank).
• rapport: a close, harmonious relationship with mutual understanding.
• portable, transport, import, export: the everyday members.

Trap: opportune and importune look like members of this family but come from Latin portus, a harbor. Opportune means well-timed; importune means to pester someone with repeated requests. Learn them as a separate pair.

cred: to believe

• credible: able to be believed; convincing.
• credulous: too ready to believe things; easily fooled.
• incredulous: unwilling or unable to believe something; showing disbelief.
• credence: belief in or acceptance of something as true (give credence to a rumor).
• credo: a statement of beliefs or principles.
• discredit: to damage the reputation of, or cause something to seem false.

The key exam distinction is between the thing and the person. A credible claim deserves belief. A credulous person believes too easily. An incredulous person refuses to believe. Mixing these up is a classic Sentence Equivalence error.

bene and mal: good and bad

• benevolent / malevolent: wishing good to others / wishing harm to others.
• beneficent: actively doing good; generous in action.
• benign: gentle and kindly; in medicine, not harmful.
• malign: as a verb, to speak harmful untruths about someone; as an adjective, evil in nature or effect.
• malfeasance: wrongdoing, especially by a public official.
• malaise: a general feeling of discomfort, unease or low energy.

This is the easiest family to learn as mirror pairs. Benevolent versus malevolent and benign versus malign stick better together than apart.

chron: time (Greek)

• chronic: persisting for a long time or constantly recurring.
• chronicle: a factual record of events in time order; as a verb, to record them.
• anachronism: something placed in the wrong period, such as a wristwatch in a film set in ancient Rome.
• synchronize: to make things happen at the same time.
• chronological: arranged in time order.

Anachronism shows how prefixes combine with roots. Ana- here means against or back, so the word describes something out of step with its time.

loqu, locu: to speak

• eloquent: fluent and persuasive in speaking or writing.
• loquacious: talkative, often too much so.
• colloquial: informal; used in ordinary conversation rather than formal writing.
• soliloquy: a speech a character makes alone, speaking thoughts aloud.
• circumlocution: using many words where a few would do; talking around a point.
• obloquy: strong public criticism, or the disgrace that results from it.
• interlocutor: a person taking part in a conversation.

Obloquy is a good example of why you still need the dictionary. The parts suggest "speaking against", which fits, but the word usually names the public disgrace itself.

voc, vok: to call

• equivocal: open to more than one interpretation, often deliberately vague; equivocate is the verb.
• vociferous: loud and forceful in expressing opinions.
• irrevocable: impossible to change or reverse.
• provocative: intended to cause a strong reaction.
• advocate: to speak publicly in favor of; a person who does so.

mut: to change

• immutable: unchanging over time or unable to be changed.
• mutable: liable to change.
• transmute: to change completely in form or nature.
• permutation: one of the possible ways a set of things can be arranged.
• commute: in law, to reduce a sentence to a less severe one; in daily use, to travel to work.

grad, gress: to step

• digress: to leave the main subject temporarily.
• transgress: to go beyond a limit, especially a moral or legal one.
• egress: a way out, or the act of going out.
• retrograde: moving backward, or returning to a worse state.
• regress: to return to an earlier, often less developed, state.

plac: to please, to calm

• placate: to make someone less angry.
• implacable: unable to be calmed; relentless (an implacable enemy).
• placid: calm and not easily upset.
• complacent: pleased with yourself in a way that makes you ignore dangers or problems.
• complaisant: willing to please others; obliging.

Complacent and complaisant come from the same Latin verb but mean different things. The first is smug; the second is accommodating.

fid: trust, faith

• fidelity: faithfulness to a person or cause; also accuracy, as in high-fidelity audio.
• confidant: a person you trust with private matters.
• diffident: shy and lacking self-confidence.
• perfidious: deceitful and untrustworthy.

Diffident is often misread as a spelling of different. The dis- prefix here means lack of: lacking trust in yourself.

culp: blame

• culpable: deserving blame.
• exculpate: to show that someone is not guilty.
• inculpate: to accuse or implicate someone in wrongdoing.
• culprit: the person responsible for a crime or problem.

ver: true

• veracity: truthfulness or accuracy.
• verisimilitude: the appearance of being true or real, especially in fiction.
• aver: to state firmly that something is the case.
• verify: to check that something is true.

Quick-reference table

Where roots mislead you

Roots are a hypothesis, not a proof. Four kinds of trap are worth knowing before exam day.

• False family members. Opportune and importune are not about carrying. Check the dictionary's origin note when a word seems to fit a family only loosely.
• Meaning drift. Specious started with appearance and ended up meaning deceptively plausible. Commute has a legal sense that has little to do with traveling to work.
• Same root, different job. Credible describes the claim, credulous the person. Complacent and complaisant share an ancestor but describe different attitudes.
• Prefix confusion. In diffident the prefix signals absence. In anachronism it signals being out of place. Learn the common prefixes alongside the roots so you read the whole word, not just the middle.

A useful habit: when you guess from a root, say the guess and then check it. Over time you will learn which families are reliable guides and which ones drift.

A study method for root families

Reading a list like this once will not make the words yours. What works is a short, repeated cycle that forces you to retrieve each word from memory and use it.

• Start from one anchor word. For each family, pick the member you already know well (predict, transport, incredible). That is your hook.
• Add three or four exam words. Learn each with a plain-English definition, one example sentence and its pronunciation. Say it out loud once.
• Guess, then check. Before you look up a new member of a family, write down what you think it means from the parts. Being wrong and then corrected is one of the more memorable ways to learn a word.
• Test yourself the next day. Cover the definitions and try to produce them. Then reverse it: read a definition and produce the word. The reverse direction is harder and closer to what Text Completion demands.
• Group by confusion. Put credulous, credible and incredulous on the same card and write one sentence that uses all three. Do the same for complacent and complaisant.
• Revisit on a widening schedule. Review after one day, a few days, a week and then a few weeks. Each successful recall can push the next review further out.

For a deeper look at how prefixes, roots and suffixes combine across English, see our practical map of English roots and affixes. If you want to know why effortful recall beats rereading, our guide to memorizing definitions fast walks through the techniques with examples.

Practice: decode these before you look them up

Try to work out each word from its parts, then check your answer in a dictionary.

• specter (spec): what might a thing that is "seen" but not really there be?
• dictatorial (dict): what kind of manager is this?
• incredulity (cred): which feeling does the audience show?
• benefactor (bene): what does this person do for a charity?
• grandiloquent (loqu): what kind of speech is this?
• immutability (mut): what property does a law of nature have?

If your guess was close, the family is working for you. If it was off, note why. That note is often what makes the word stick.

Building a GRE and TOEFL plan around families

A realistic pace for most test-takers is one or two new families a week, with the rest of the time spent reviewing and meeting the words in real reading. Aim for four to six words per family that you can define, pronounce and use in a sentence. After eight to ten weeks you will have a web of well-learned words rather than a long list of half-recognized ones.

Keep a running page for each family and add new members whenever practice questions or reading passages throw one up. On the GRE, when a Sentence Equivalence question includes an unfamiliar word, ask which family it belongs to and whether the meaning fits the sentence's direction. On the TOEFL, use the family to form a quick hypothesis and then confirm it from the surrounding sentences.

Apps can take care of the scheduling. WordFren, for example, brings each word back in fill-in-the-blank Recall and spaced review, and its Vocabulary Journey runs up to SAT and GRE level, so you can pair it with the family pages you keep yourself. Whatever tool you use, the principle is the same: learn words in connected groups, test yourself instead of rereading, and keep going back to them until they come to mind without effort.