Dr. Richard Nordquist is professor emeritus of rhetoric and English at Georgia Southern University and the author of several university-level grammar and composition textbooks.
Updated on July 10, 2024A prefix is a letter or a group of letters attached to the beginning of a word (or word root) that partly indicates its meaning. For example, the word prefix itself begins with the prefix pre-, which generally means "before" or "in front of" (by contrast, a letter or group of letters attaching to the end of a word is called a suffix).
Many of today's English words contain prefixes from Greek or Latin. Understanding the meanings of the most common prefixes can help us deduce the definition of new words we run across in our reading, especially knowing a prefix can make a word mean its opposite, such as the difference between "possible" and "impossible".
Still, we do need to be careful. The same prefix may be spelled in more than one way (pre- and pro-, for instance), and some prefixes (such as in-) have more than one meaning ("not" or "without" versus "in" or "into," as an example). Even so, being able to recognize prefixes can help us build our vocabularies and parse out words we may not know.
Rules vary as to when a word should have a hyphen separating it from its prefix. Go by the dictionary if you are unsure. If you are writing a paper for a class and a particular style guide is used, such as MLA, the Chicago Manual of Style, or APA, the stylebook may have a hyphenation guide or a preferred dictionary to follow for which words to hyphenate and which to close up. If a prefix is attached to a proper noun, you generally hyphenate, such as pre-World War II or anti-American.
The following table defines and illustrates 36 common prefixes.
| Prefix | Meaning | Examples |
| a-, an- | without, lack of, not | amoral, acellular, abyss, achromatic, anhydrous |
| ante- | before, earlier, in front of | antecedent, antedate, antemeridian, anterior |
| anti- | against, opposite of | anticlimax. antiaircraft, antiseptic, antibody |
| auto- | self, same | autopilot, autobiography, automobile, autofocus |
| circum- | around, about | circumvent, circumnavigate, circumscribe |
| co- | with, together | co-pilot, co-worker, co-exist, co-author |
| com-, con- | together, with | companion, commingle, contact, concentrate |
| contra-, contro- | against, opposite | contradict, contrast, contrary, controversy |
| de- | down, off, away from | devalue, deactivate, debug, degrade, deduce |
| dis- | not, apart, away | disappear, disagreeable, disbar, dissect |
| en- | put into, cover with | enclose, entangle, enslave, encase |
| ex- | out of, from, former | extract, exhale, excavate, ex-president |
| extra- | beyond, outside, more than | extracurricular, extramarital, extravagant |
| hetero- | different, other | heterosexual, heterodox, heterogeneous |
| homo-, homeo- | same, alike | homonym, homophone, homeostasis |
| hyper- | over, more, beyond | hyperactive, hypersensitive, hypercritical |
| il-, im-, in-, ir- | not, without | illegal, immoral, inconsiderate, irresponsible |
| in- | in, into | insert, inspection, infiltrate |
| inter- | between, among | intersect, interstellar, intervene, interpenetrate |
| intra-, intro- | within, inside | intravenous, intragalactic, introvert |
| macro- | large, prominent | macroeconomics, macrostructure, macrocosm |
| micro- | very small | microscope, microcosm, microbe |
| mono- | one, single, alone | monocle, monologue, monogamy, monotony |
| non- | not, without | nonentity, nonaggressive, nonessential, nonfiction |
| omni- | all, every | omniscient, omnivorous, omniscient, omnidirectional |
| post- | after, behind | postmortem, posterior, postscript, postoperative |
| pre-, pro- | before, forward | precede, predict, project, prologue |
| re- | again | reelect, readmit, resubmit |
| sub- | under, lower | submarine, subsidiary, substandard |
| sym-, syn- | same time, together | symmetry, symposium, synchronize, synapse |
| tele- | from or over a distance | telecommunications, telemedicine, television, telephone |
| trans- | across, beyond, through | transmit, transaction, translation, transfer |
| tri- | three, every third | tricycle, trimester, triangle, triathlon |
| un- | not, lacking, opposite of | unfinished, unskilled, ungraceful, unfriendly |
| uni- | one, single | unicorn, unicellular, unicycle, unilateral |
| up- | to the top or north, higher/better | upbeat, updo, upgrade, upload, uphill, upstage, upscale, up-tempo |
Lastly, the general rule is to use the whole prefix in a word—as in, refrain from adding or removing letters.
Cite this Article Your CitationNordquist, Richard. "36 Common Prefixes in English." ThoughtCo, Jul. 10, 2024, thoughtco.com/common-prefixes-in-english-1692724. Nordquist, Richard. (2024, July 10). 36 Common Prefixes in English. Retrieved from https://www.thoughtco.com/common-prefixes-in-english-1692724 Nordquist, Richard. "36 Common Prefixes in English." ThoughtCo. https://www.thoughtco.com/common-prefixes-in-english-1692724 (accessed September 12, 2024).
copy citation 100 Key Terms Used in the Study of Grammar A List of Exclamations and Interjections in English What Is a Phrase? Definition and Examples in Grammar The 201 Most Commonly Misspelled Words in English What Are Contractions? What Are Word Blends? Past Participles in English Grammar 100 Awfully Good Examples of Oxymorons Commonly Confused Words: Inhuman and Inhumane What Is Composition? Definition, Types, and Examples Basic Grammar: What Is a Diphthong? To, Too, and Two: How to Choose the Right Word Figure of Speech: Definition and Examples Definition and Examples of Function Words in English How to Write a Summary (With Examples) Deverbal Nouns and Adjectives in English GrammarWe and our 100 partners store and/or access information on a device, such as unique IDs in cookies to process personal data. You may accept or manage your choices by clicking below, including your right to object where legitimate interest is used, or at any time in the privacy policy page. These choices will be signaled to our partners and will not affect browsing data.
Store and/or access information on a device. Use limited data to select advertising. Create profiles for personalised advertising. Use profiles to select personalised advertising. Create profiles to personalise content. Use profiles to select personalised content. Measure advertising performance. Measure content performance. Understand audiences through statistics or combinations of data from different sources. Develop and improve services. Use limited data to select content. List of Partners (vendors)