60 Most Common Prefixes List – with Meanings

What does it mean for a political speech to be “equivocal”? In the absence of Google, you could use the prefix in equivocal to understand its definition. Prefixes are parts of words that are added at the beginning of base or root words to change their meaning. For example, “equi-” is one of the most common prefixes in English and means “equal.” When added to the word “vocal,” which means the act or quality of expression, it results in a word that describes expressions equally open to multiple interpretations. Thus, you could understand that a politician who makes an equivocal speech is obscuring their actual position on an issue. And you can understand this simply by appreciating how the prefix changes the word it’s attached to (see Prefix List below for more examples).

Despite their dizzying number, prefixes are a terrific way to improve reading comprehension. Learning what these prefixes mean can be beneficial when encountering unknown words. It also can help you develop a more robust vocabulary through learning a variety of words that use prefixes. This article lists the most common prefixes you’ll encounter in the English language. It identifies 10 common prefixes that are similar in having numerical meanings. It also considers the rather odd case of the common prefix “be-” and what makes it so unusual.

Prefixes vs. Suffixes

We encourage you to also visit our list of the most common suffixes in English. Suffixes similarly join lots of different words to change their meaning, but they come at the ends of words. In the example above, “equivocal” uses the suffix “-al” (meaning like). Suffixes can notably alter the spelling of the words they modify. Thankfully, prefixes involve no such spelling contortions. Learning prefixes and suffixes together is a surefire way to improve your reading comprehension (prefix “com-”, suffix “-ion”).

Things to Consider about Using Prefixes in English

Before we get to the list (which you’re dying to read), let’s consider the difficulties that arise when using prefixes. There are a few complications involved in learning prefixes, their meanings, and how they attach to words. Firstly, certain common prefixes don’t have one settled meaning, but instead multiple meanings. For example, the prefix “in-” can mean “in,” as it does in the word “influx” which means a flowing in. But it can also mean “not,” which we see in the word “invalid” or not valid.

There is also the difficulty of understanding which prefixes attach to which base words or roots. A base word is a word that can stand alone and has meaning without a prefix or suffix (like “help”). Similarly, a root is a part of a word that a prefix modifies, but which doesn’t necessarily have independent meaning. For instance, the root of the word “envelope” is “velope,” which doesn’t mean anything without its prefix “en-.” There are innumerable base words and roots that use prefixes, and many that can use multiple prefixes. However, it’s not as simple as adding any prefix you know to any base word or root. Base words and words come with a fixed set of prefixes that can be used to change their meaning. In other words, you must know the meanings of prefixes and which base words or roots they typically modify.

Most Common Prefixes in English (Continued)

In the list below, it is indicated when a prefix signifies different ideas, with examples using each meaning. The examples included can also help in learning which base words and roots go with which common prefixes. You can also check out our lists of the top 130 GRE vocabulary words and 250 SAT vocabulary words if you are eager to add more words that use prefixes to your vocabulary.

The Most Common Prefixes in English

The following is an alphabetized list of 50 of the most common prefixes with definitions and examples. Following this list is a section that defines the 10 most common prefixes in English with numerical meanings. If you make it all the way to the end of these 60 listed prefixes, you can read about one of the most common (and strangest) prefixes.

Most Common Prefixes—the List:

1. A- (or ab-): without or not (amoral, ahistorical, abnormal, atypical)
2. Ab-: away (absent, abdicate, aberrant, abject)
3. Ad-: to, forward (advance, admit, adventure, adjust)
4. Ante-: before (antecedent, antechamber, antebellum)
5. Anti-: against (antisocial, antipathy, anticlimax, antiestablishment)
6. Auto-: self (autonomy, autocracy, autodidact, automotive)
7. Circum-: round, around (circumvent, circumscribe, circumference, circumnavigate)
8. Com- (or co-/con-): with, together (compact, co-author, conclave, confluence)
9. Contra- (or counter-): against (contravene, contrary, contrapuntal, counteract)
10. De-: down, off, reversed (deactivate, deconstruct, descend, derail)
11. Dia-: through (dialogue, diagnose, diaphanous, dialect)
12. Dis-: not (disjointed, dissent, disavow, disown)
13. E-: out of (eject, emit, edict, erect)
14. En-: put into, cover (envelope, encase, enclose, enlist)
15. Ex-: out of, from (excavate, extract, exclaim)
16. Equi-: equal (equidistant, equivocal, equity)
17. Extra-: above, outside (extraneous, extraterrestrial, extravagant)
18. Hetero-: different (heterogenous, heterodox)
19. Homo-: same (homonym, homophone, homogenous)

Most Common Prefixes in English (Continued)

20. Hyper-: over (hypersensitive, hyperactive, hyperbolic)
21. Il-: not (illegitimate, illegible, illegal)
22. Im-: not (impossible, immoderate, immoral)
23. In-: in or not (inspect, invisible, incorrect)
24. Intra-: within (intrastate, intravenous, intracellular)
25. Inter-: between or among (interstate, international, intervene)
26. Ir-: not (irresponsible, irreverent, irreligious)
27. Magni-: large (magnitude, magnanimous, magnificent)
28. Micro-: small (microscope, microcosm, microwave)
29. Mis-: wrong (misunderstand, misfit, mismanage)
30. Mono-: one (monologue, monopoly, monoculture)
31. Multi-: many (multicolored, multicultural, multiply)
32. Neo-: new (neophyte, neologism, neonatal)
33. Non-: not (nonfiction, noncommittal, noncomformist)
34. Ob-: against (obstruct, obstinate, obdurate)
35. Over-: too much (overestimate, overkill, overachieve)
36. Pan-: all (pandemonium, panacea, Pan-African)
37. Per-: through (pervade, permeate, permit)
38. Peri-: around (perimeter, pericardium, periscope)
39. Poly-: many (polyglot, polygon, polycarbonate)

List (Continued)

40. Post-: after (postpone, postlapsarian, postmodern)
41. Pre-: before (preplan, prewrite, previous)
42. Pro-: forward (progress, propellant, promote)
43. Pseudo-: false (pseudonym, pseudointellectual, pseudoscience)
44. Re-: again or back (revisit, reject, return)
45. Retro-: backward (retrospective, retroactive, retrograde)
46. Sub-: under (submerge, submarine, subject)
47. Super-: over (supernatural, superb, superior)
48. Sym- (or syn-): with or together (synthetic, synchronize, symphony)
49. Trans-: across (transatlantic, transform, transport)
50. Un-: not (unsuccessful, unnerving, unnatural)

Common Prefixes in English with Numerical Meanings

There are many prefixes in English that refer to numerical amounts. You’ll often encounter some of these prefixes using various systems of measurement. For example, in the metric system length and volume are often signified in numerical terms using prefixes (i.e. “centimeter” and “milliliter”). While the below list focuses on the most common numerical prefixes, you should be aware it is not comprehensive. In fact, a reporter for NPR wrote about the emergence of brand-new prefixes in the field of data science. It turns out we are generating enough data to necessitate prefixes like “ronna” (27 zeroes) and “quetta” (30 zeroes)

For now, let’s consider the numerical prefixes in English you’ll encounter most. These can be useful whether you are measuring your height or talking about the Lord of the Rings trilogy.

1. Bi-: two (bifocal, bisect, bilateral)
2. Cent-: 100 (century, centigrade, centimeter)
3. Dec-: ten (decade, decimal, decalogue)
4. Hemi-: half (hemisphere, hemitrope)
5. Kilo-: 1,000 (kilometer, kilogram, kilobyte)
6. Milli-: 1,000 (millipede, millisecond, millions)
7. Quad-: four (quadruple, quadrant, quadriplegic)
8. Semi-: half (semicircle, semiannual, semiformal)
9. Tri-: three (triangle, trilogy, triple)
10. Uni-: one (uniform, univocal, unisex)

The Most Curious of Common Prefixes: “Be-”

Most of the common prefixes in English can be defined using one or two words. “Auto-” means self, “counter-” means against, and “re-” means again or back. But there is one common prefix trickier to define: “be-.” Like many other prefixes, the “be-” prefix is ancient, stemming from Old English. It’s used in words that have disappeared from common use like “betwixt.” We also see it in bewildering and bedeviling number of words we use daily. In other words, what began in Old English has become an oddity in modern usage. The problem is that “be-” has a wide range of meanings based on the words it is joined to. As the Online Etymology Dictionary clarifies, “be-“ can mean “about, around; thoroughly, completely; to make, cause, seem; to provide with; at, on, to, for.” It can also turn a range of nouns and adjectives into verbs: “befriend, befit, benumb.”

For the sake of clarity, “be-” is not included in the list above. But you should be aware that it is a strong contender to be the most common prefix in the English language.

Final Thoughts

Common prefixes are everywhere if you know to look for them. It can be exceedingly helpful to know the meanings of prefixes if you frequently encounter unfamiliar words. In those circumstances, you can use the prefix to get yourself halfway to knowing the meaning of the word.

However, you can also think of prefixes as a way of grouping together vast numbers of common and obscure words. In making this list, it was fun to try to brainstorm as many words as I could for each prefix. Afterward, I found myself self-consciously registering words with prefixes that I was using. All this is to say that appreciating common prefixes can be a great way to begin discovering all the words that use them.

As with any skill set, vocabulary only improves with regular practice. Once you recognize a prefix, brainstorm as many examples of words that use it as you can. Then crack open a dictionary. Then start applying those words in your daily life. The best way to learn the many vocabulary words with prefixes is to regularly use them in conversation or writing. If your friends think that’s pretentious of you, you’ll be able to explain how anti-intellectual (“anti-”: against) they are.