This list of prefixes, along with some common roots and suffixes, can help you recognize hundreds of words. Work with some of these 50 or so prefixes, or a few Latin roots, every day, and watch your English vocabulary take off!
(Click here to go straight to the prefix list and save the explanations for later.)
1. There are often several prefixes with the same meaning, one from Latin and one from Greek, maybe even one from Anglo-Saxon (as with sub-, hypo-, and under-.) Often-- but not always-- they are used with a root from the same language. So we have ‘synthesis’ originally from Greek and ‘composite’ from Latin, both combining ‘with’+ the idea of setting down or placing something.
However, prefixes and roots don't have to match. 'Hyper,' (‘over’ or ‘excessive’ in Greek) can be combined with ‘active,’ from Latin, to make the common English word 'hyperactive.' See Common Greek and Latin Prefixes to compare these (and a few less common) synonym prefixes, in alphabetical order by English meanings.
2. Prefixes are commonly used to indicate size (macro, micro), quantity (mono, uni, bi, tri, quad, multi, poly), relationships (anti, contra, com, sym), position in time (ante, fore, pre, post) or space (circum, exo, inter, intra, peri, sub, trans, etc.), quality (eu, mal), or negation. (See Negative Prefix List for a more detailed discussion.)
3. Several prefixes have more than one form, usually because a different ending sounds better before certain letters. These include a- or an-, ad- (which often drops the ‘d’ and may double the consonant of the root word); co-, com-,or con-; il-, im-, in-, ir; pre-, pro-; sym-, syn-; and sometimes others, like sub-.
4. There are many more commonly-used prefixes. I tried to limit this list of prefixes to the most useful of all, so it would be short enough to learn easily. (You can find more complete lists on the Internet or in a good dictionary.)
After you read the definition and the examples for each prefix, try to think of another word or two made from it. For example: anonymous-- without a (known) name, abduct-- to “lead away” (move your arm or leg away from the body, or to kidnap someone from their home), adhesive, adjust or administer ...
Some prefix meanings will be obvious. Others will make more sense as you learn more words. See 50 Word Roots from Latin for prefixes combined with the Latin verb mittere, and then with other roots.
|a-, an-||without, not||anesthetic, atheist|
|ab-||away, from||abject, abscess|
|ad-, a-, ac-, as-||to, toward||access, admit, assist|
|bi-||two, both||bifocals, bipolar|
|co-, com-, con-||with||companion, concurrent|
|contra-, counter-||against||contradict, counteract|
|de-||not, from, down||degenerate, depress|
|di-, dis-||lack of, not, apart||disadvantage, displacement|
|eu-||good, normal||eugenics, eulogy|
|ex-||out (of), former||expose, extract|
|exo-, ecto-, extra-, extro-||outside||exoskeleton, extraordinary|
|hyper||above, excessive||hyperactive, hypertension|
|hypo-||under, insufficient||hypodermic, hypothetical|
|il-, im-, in-, ir-||in, into, not, against||illegitimate, inadequate|
|inter-||among. between||interpose, intervene|
|non-||not, lacking||nonfat, nonsense|
|ob-,o-, oc-, op-||against, over, completely||object, occur, omit, oppose|
|pre-||before||precede, predict, prevent|
|re-||again, back||reform, retain, regenerate|
|semi-||half, partially||semiannual, semiconscious|
|super-, supra-||above, excessive||superlative, suprarenal|
|sym-, syn-||with, together||sympathy, synthetic|
|trans-||across, beyond||Transform, transportation|
|ultra-||beyond. excessive||ultraliberal, ultrasonic|
This table, as well as information and practice on these prefixes, is also available as an inexpensive pdf for classes on Root, Prefix, and Suffix Worksheets. You can also get a similar version of just the prefix table and negative prefix list here. (Right-click to download.)
Word Families shows you how these prefixes change one word family (act), and 50 Latin Word Roots shows how they are used with many roots, as well as giving a complete demonstration with one. You might also like English Word Origins, List of Suffixes or Important Latin Roots.