Grammar Tip! What is a prefix?

A prefix (affix) is a word, or letter(s) placed at the beginning of another word (a base word) to adjust or qualify its usage or meaning. The opposite of prefix is suffix. Feel free to experiment with prefixes during conversation in class.

List of English Prefixes Prefix General Meaning Example a(n)- not , without atonality , asexuality , amoral , anarchy ab- away abduction , absolutism , ablution ac- acr(o)- high, up Acropolis aden(o)- aer(o)- air aeronautics , aerodrome , aeroplane , aerodynamics agr(o)- relating to farming agriculture an- an(a)- out of anachronism an(o)- andr- man androgyny , androcentrism , android , androgen anem- Anglo- English or British Anglo-Irish relations, anglophile ante- before antebellum anthrop(o)- relating to human beings anthropology , anthropocentrism , anthropomorphic ant(i)- against antidote , antibody , anticlockwise aut(o)- self autonomy , autobiography , automobile , autopilot bar(o)- atmosphere bathy- deep Bathyscape , Bathysphere be- completely, thoroughly; excessively; on; around; about; used to form transitive verbs bi- two bicycle , bijection , bilingual , bicameralism , bisexuality bi(o)- life biology , biography , biosphere , biotechnology bibli(o)- relating to books bibliophilia , bibliography blast(o)- brady- slow bradycardia brom(o)- bronch(o)- relating to breathing bronchitis cac(o)- cardi(o)- heart cardiovascular cent-, centi - hundred or hundredth centenary, centimeter, centipede cephal(o)- chrom(o)-, chromat(o)- chron(o)- time chronology, chronograph circum- around circumcision, circumnavigation, circumlocution, circumference cion(o)- co- together cooperative, cohabit colpo- com-, con-, col-, cor- with, together conference , connotation , context , Congress , congregation contr(a)-, contr(o) against, opposite contradiction , contraception , controversy cosm(o)- cosmology , cosmopolitan , cosmotheism counter- against, opposite counterpoint , counterweight , Counter-Reformation crin(o)- cry(o)- frost , icy cold cryogenics , cryoelectronics , cryostorage crypt(o)- hidden cryptography , cryptozoology cyt(o)- hollow, receptacle, cell cytoplasm , cytology dactyl(o)- de- taking something away, the opposite decentralisation , deforestation , dehydration dec(a)-, dek(a)- ten decamerous deci - one tenth deciliter dem(o)- people, nation demographics , democracy derm(o)-, derm(a)-, dermat- skin dermatology , dermatitis di- two , double didact(o)- apt at teaching dynam(o)- power , force dynamic , dynamite , dynamo dis- reverse , opposite dissent , discovery , disambiguation dox(o)- Doxology dys- bad, deformed, abnormal dyspepsia , dystrophy , dysarthria eco- house economy , ecology , ecosystem , ecotourism , ecotage ecto(s)- outside ectoskeleton edaph(o)- electr(o)- electricity electrocution embry(o)- full encephal(o)- brain encephalitis end(o)-, ent(o)- enne(a)- nine enneastyle enter(o)- eo- dawn, early eobacterium ep(i)-, eph- above epitaxy erg(o)- ergonomics erythr(o)- erot(o)- stom(o)-, stomat(o)- ethn(o)- ethnology , ethnolinguistics , ethnocentrism eu- good eulogy , euthanasia , eugenics , euphemism ex- former ex-wife, ex-president ex(o)- outside exoskeleton extra- very, more than usual, outside, beyond extra-thin, extra-specialextraordinary, extraterrestrial flor(i)- relating to flowers florist fore- before, in advance foreskin , foreshadowing gyn- female gynaecology , gynoid hemi- half hemimetabolous hex(a)- six hexapod hyper- excessive, (least to greatest in order: hypo, sub, super, hyper) hyperactive , hyperthyroidism hyp(o)- below, (least to greatest in order: hypo, sub, super, hyper) hypodermic in- extremely inflammable , invaluable in-, il-, im-, ir- not infallibility , illiteracy , immoral , irrelevant inter- between, from one to another intervention , international intra- within, interior intramural, intravenous kilo - thousand kilogram , kilowatt mal- bad, badly malpractice , malnutrition maxi- most, very, large maxi-dress mega -, megal- million , very large megabyte , megaphone meta- after, beyond metacarpal , metaphysics micro - one millionth, very small microgram , microorganism , micronation mid- in the middle of mid-term elections , Mid-Autumn Festival , Mid-Atlantic Ridge milli - thousandth milligram , milliliter mini- small miniskirt , miniscule mis- bad , wrong miscarriage , misanthropy , misogyny mon(o)- one , single monolith , monorail , monotony , monocle multi- many multiculturalism , multilingual non- not nonsense, non-denial denial non- nine none, nonagon oct(o)-, oct(a)- eight octane , octopod , octagon oo- (" oo -oh") egg, ovum oocyte out- more, to  a  greater degree to outdo, to outrun over- more than normal, too much overpopulation , over-consumption pent(a)- five pentagon post- after Post-Fordism , postpartum depression , postmodernity , postmodernism pre- before prediction , preview , precedent , prenatal care pro- for, in favour of pro-choice, pro-life, promotion quadr-, quart- four quadrangle , quadruplet , quartic , quartile quin(que)- five , into five parts quinquesection quint(i)- fifth , five quintiped re- again, repeatedly reduction , reflection , revolution rect(i)- proper, straight rectify, rectangle scler(o)- hard scleroderma atherosclerosis semi- half semi-automatic , semi-detached sept(a)- seven heptachord sex(i)- six sexivalent Sino- Chinese Sino-American relations spasm(o)- sperm(o)-, spermat(o)- spher(o)- sphygm(o)- pulso sphygmomanometer splen(o)- splanchn(o)- schiz(o)-, schist(o)- split schizophrenia , schistocyte staphyl(o)- styl(o)- pillar sub- below, less than, under,(least to greatest in order: hypo, sub, super, hyper) subset , subsonic , subway , subtitles super- extremely, more than, (least to greatest in order:hypo, sub, super, hyper) superhuman , Superego , supersonic syn- along with, together, at the same time synergy , synchronicity tach(y)-, tach(o)- fast, speed tachycardia , tachometer tel(e)-, tel(o)- far, over  a  long distance telecommunications , television , telephoto lens , telodynamic tel(o)-, tel(e)- end, complete, mature teloblast trans- across, beyond transfer , transubstantiation , transatlantic , Trans-Siberian railway tri- three triangle , tricolor , triptych ultra- extremely, beyond  a  certain limit Ultramontanism , ultraviolet un- not, opposite, take something away unconstitutional , undelete uni- one , single uniform , unification ur- first, original urtext zoo- (" zoo -oh") relating to animals zoomorphic , zoology