Common Prefixes
40 building blocks that unlock thousands of words.
A prefix is a group of letters added to the start of a word to change its meaning. English has borrowed prefixes from Latin, Greek, Old English and French — and once you know the 40 most common ones, you can guess the meaning of tens of thousands of words you've never seen.
This reference lists each prefix with its meaning, origin, three examples and a note on how it behaves. It's designed to be scanned, bookmarked, and used as a lookup during word games.
Negation & reversal
| Prefix | Meaning | Origin | Examples |
|---|---|---|---|
| UN- | not / reverse | Old English | unhappy, undo, unfair |
| IN- | not / into | Latin | invisible, insert, inedible |
| IM- | not (before b, m, p) | Latin | impossible, immature, imbalance |
| IL- | not (before l) | Latin | illegal, illiterate, illogical |
| IR- | not (before r) | Latin | irregular, irrelevant, irresponsible |
| DIS- | not / apart | Latin | disagree, disappear, disconnect |
| NON- | not / absence | Latin | nonfiction, nonstop, nonsense |
| MIS- | wrong / bad | Old English | misunderstand, misplace, misread |
Quantity & number
| Prefix | Meaning | Examples |
|---|---|---|
| MONO- | one | monologue, monopoly, monorail |
| BI- | two | bicycle, bilingual, binary |
| TRI- | three | triangle, tripod, trilogy |
| QUAD- | four | quadrant, quadruple |
| PENT- | five | pentagon, pentathlon |
| HEX- | six | hexagon, hexameter |
| OCTA- | eight | octopus, octave |
| DEC- | ten | decade, decimal, decathlon |
| MULTI- | many | multitask, multimedia, multitude |
| POLY- | many | polygon, polymath, polyglot |
Time & sequence
| Prefix | Meaning | Examples |
|---|---|---|
| PRE- | before | prehistoric, preview, prepare |
| POST- | after | postpone, postscript, postgraduate |
| ANTE- | before | antecedent, antechamber |
| FORE- | before / front | forecast, foresee, foreword |
| RE- | again / back | redo, return, review |
Position & direction
| Prefix | Meaning | Examples |
|---|---|---|
| SUB- | under | submarine, subtract, subway |
| SUPER- | above / beyond | supervisor, supernatural, superscript |
| INTER- | between | international, interact, intersect |
| INTRA- | within | intranet, intrapersonal |
| TRANS- | across | transport, translate, transatlantic |
| CIRCUM- | around | circumnavigate, circumference |
| EX- | out / former | export, exhale, ex-president |
| IN- | into | include, invade, insert |
Degree & intensity
| Prefix | Meaning | Examples |
|---|---|---|
| OVER- | too much | overreact, overeat, overwhelm |
| UNDER- | too little | underestimate, undercook |
| HYPER- | above / extreme | hyperactive, hyperbole |
| HYPO- | below / under | hypothermia, hypothesis |
| MEGA- | large | megabyte, megacity |
| MICRO- | small | microscope, microwave |
| MINI- | small | minibus, minimarket |
| ULTRA- | beyond | ultraviolet, ultramodern |
Attitude
| Prefix | Meaning | Examples |
|---|---|---|
| ANTI- | against | antibiotic, antihero, antisocial |
| CO- | together | cooperate, coauthor, coexist |
| CON- | with | connect, contract, converse |
| PRO- | for / forward | proactive, promote, propose |
| AUTO- | self | autobiography, autopilot |
Using prefixes in word games
In Scrabble and Words With Friends, prefixes are the difference between a 20-point play and a 50-point bingo. If your rack contains RE-, PRE-, UN-, DIS- or MIS-, you can extend existing board words for large scores. RE- attaches to almost any verb (REPLAY, REBUILD, REDO); UN- attaches to almost any adjective (UNHAPPY, UNSURE).
Summary
- ✓40 common prefixes account for the majority of prefixed English words.
- ✓Learn a prefix's meaning once and you can guess hundreds of words.
- ✓RE- and UN- alone attach to thousands of English verbs and adjectives.
- ✓In word games, spotting a prefix on your rack is often a bingo signal.
Frequently asked questions
How many prefixes are there in English?
Around 50 productive ones (that still make new words), plus dozens of specialised technical ones.
What's the most common prefix?
UN- and RE- together account for over 40% of prefixed words in modern English text.
Why do some prefixes have variants (IN-, IM-, IL-, IR-)?
Latin assimilation — the /n/ sound adapts to the following consonant. IN- becomes IM- before b, m, p; IL- before l; IR- before r.
Are prefixes always hyphenated?
In modern English, usually not — ‘nonstop’, ‘preheat’, ‘recount’. Hyphens survive mainly to avoid confusion (‘re-cover’ vs ‘recover’) or before proper nouns (‘anti-Trump’).
References & further reading
- Merriam-Webster Dictionary — general English word validity and definitions.
- Collins English Dictionary — source lexicon for SOWPODS / Collins Scrabble Words.
- Wiktionary — collaborative dictionary with usage notes and etymologies.
- Moby Project (Wikipedia) — background on the ENABLE word list used by our tool.
- See Content Standards for the full list of dictionary sources and how content is reviewed.
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