English Root Words: How 1 Root Becomes 10 New Words (A TOEFL Vocabulary Trick)
English root words for TOEFL vocabulary: how DICT, PORT, and VIS plus prefixes like re-, un-, pre- and suffixes like -tion, -able build new words.
Feel like your English vocabulary isnât growing even though you memorize words every day? The problem may be the method. Memorizing words one by one is hard. It gets much easier when you learn the root, then see how prefixes and suffixes change it.
Many academic English words come from Latin and Greek and are built from the same pieces. Once you know one root, you can guess the meaning of a dozen or more words built on it. This helps a lot in TOEFLÂź ITP Reading, especially vocabulary in context questions. (The slides below are in Indonesian, with the English words.)
What Is a Root Word?
An English word is often made of three parts:
- Prefix: changes the meaning. Example: un- (not).
- Root: carries the core meaning. Example: dict (say).
- Suffix: usually changes the word class. Example: -able (can be ___ed).
Take predict (pre- before + dict say = âto say beforehandâ, that is, to foretell). One word gives you many others:
| Word | Word class | Meaning |
|---|---|---|
| predict | verb | to foretell |
| prediction | noun | a forecast |
| predictor | noun | something that predicts |
| predictable | adjective | able to be predicted |
| unpredictable | adjective | not able to be predicted |
| predictably | adverb | as expected |
| unpredictably | adverb | in an unexpected way |
| predictability | noun | the quality of being predictable |
| unpredictability | noun | the quality of being unpredictable |
| predictive | adjective | used to predict |
Thatâs what â1 root = 10 new wordsâ means. Every meaning still links back to the root, so youâre never starting from zero.
3 Must-Know Roots
DICT = say
From Latin dicere (to say).
- predict: to say beforehand, to foretell
- dictionary: a book of words
- contradict: contra (against) + dict, to say the opposite
- dictate: to say aloud for someone to write, to give orders
- verdict: a judgment (literally âa true sayingâ)
PORT = carry
From Latin portare (to carry).
- transport: trans (across) + port, to carry from one place to another
- export: ex (out) + port, to send goods out of a country
- import: im (in) + port, to bring goods in
- portable: able to be carried
- report: re (back) + port, to carry back news
VIS = see
From Latin videre / visum (to see).
- visible: able to be seen, invisible: not able to be seen
- vision: the ability to see, a vision
- visual: related to seeing
- revise: re (again) + vis, to look at again and change
- supervise: super (over) + vis, to oversee
Common Prefixes
| Prefix | Meaning | Examples |
|---|---|---|
| re- | again, back | redo, rewrite, review |
| un- | not | unhappy, unable, unclear |
| pre- | before | preview, predict, prepaid |
| mis- | wrongly | mistake, misunderstand, mislead |
In sentences:
The professor asked us to rewrite the essay. (write again)
The instructions were unclear. (not clear)
Many people misunderstand the theory. (understand wrongly)
Careful: not every opening letter group is a prefix. The re in ready and the un in uncle are not prefixes. A prefix only counts when the rest of the word also carries a related meaning.
Common Suffixes
| Suffix | Function / meaning | Examples |
|---|---|---|
| -tion | forms a noun | prediction, education, attention |
| -able | adjective, âcan be ___edâ | predictable, portable, readable |
| -less | adjective, âwithoutâ | careless, fearless, endless |
| -ment | forms a noun | development, improvement, achievement |
Suffixes donât just add meaning; they also change the word class. That helps twice in TOEFL: in Reading to guess meanings, and in Structure to decide whether a slot needs a noun, verb, adjective, or adverb. (See also Parts of Speech 101.)
Using Roots in TOEFL Reading
Say you meet this sentence in a Reading passage:
The new medicine produced effects that were completely unforeseeable.
You may never have seen unforeseeable. Break it down:
- un- = not
- fore = before (as in forecast)
- see = see
- -able = can be ___ed
Result: ânot able to be seen beforehandâ, in other words unpredictable. Answer choices like unpredictable or unexpected immediately look right.
Remember, though, root analysis is a helper, not a guarantee. Always check your guess against the context, because some words have drifted far from their roots.
Tips to Make It Stick
- Learn the root first, then its branches. Group words by root, not alphabetically.
- Read example sentences, donât just memorize translations. Words seen in context are easier to remember and use.
- Practice a little, regularly, for example 15 minutes a day. Spaced review beats cramming the night before the test.
ETS doesnât publish an official vocabulary list for TOEFL ITP. What you can do is build your academic vocabulary (words common in science, history, and social science texts), and the root-word trick makes that much lighter.
Summary
| Part | Examples | Meaning |
|---|---|---|
| Root | dict, port, vis | say, carry, see |
| Prefix | re-, un-, pre-, mis- | again, not, before, wrongly |
| Suffix | -tion, -able, -less, -ment | noun, can be ___ed, without, noun |
Quick Quiz
Guess the meaning from the parts:
- portable
- misinterpret
- invisible
- contradict
Answers:
- Able to be carried (port + -able).
- To interpret wrongly (mis- + interpret).
- Not able to be seen (in- + vis + -ible).
- To say the opposite, to deny (contra + dict).
Practice Academic Vocabulary
The root-word trick works best combined with regular practice.
Kawan EPT (formerly Kawan TOEFL) has 1,800 academic vocabulary flashcards with spaced repetition, Reading Strategies lessons on 11 topics, and 7,400+ questions with explanations for every answer choice. Free on the Google Play Store.
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