The word-parts that build the most words, most used to least. The number = how many words use it.
| Part | Words | For example |
| co- | 2623 | co-ed, co-op, coach, coact, coapt, coast |
| un- | 2259 | unarm, unary, unbar, unbox, uncle, uncus |
| in- | 1786 | in(a), in(p), inane, inapt, incan, incur |
| re- | 1679 | reach, react, ready, realm, rearm, reata |
| de- | 1487 | deary, death, debar, debit, debug, debut |
| dis- | 665 | disarm, disbar, disbud, discus, dished, dismal |
| ex- | 581 | exact, exalt, excel, exert, exile, exist |
| en- | 571 | enact, enate, ended, endow, endue, enema |
| bi- | 469 | bialy, bible, bibos, biddy, bidet, bifid |
| im- | 436 | image, imago, imaum, imbed, imbue, imide |
| pre- | 436 | preach, precis, prefab, prefer, prefix, prelim |
| non- | 388 | nonage, noncom, nonfat, non-jew, nonaged, nonagon |
| over- | 280 | over(p), overact, overage, overall, overarm, overawe |
| tri- | 267 | triage, tribal, tricky, tricot, trifid, trifle |
| sub- | 250 | subdue, sublet, submit, suborn, subset, subtle |
| inter- | 220 | interact, intercom, interest, interior, intermit, intermix |
| self- | 213 | selfish, selfless, self-heal, self-help, self-love, self-made |
| mis- | 207 | miscue, misery, misfit, mishap, mishna, mislay |
| anti- | 182 | antigen, antigua, antilog, antioch, antique, antiacid |
| trans- | 172 | transact, transect, transept, transfer, transfix, transmit |
| out- | 169 | out(a), out(p), outage, outbid, outcry, outfit |
| under- | 148 | under(a), underact, underage, underarm, underbid, undercut |
| super- | 125 | superbia, superbly, superbug, superego, superhet, superior |
| up- | 114 | up(a), up(p), upend, upper, upset, upupa |
| micro- | 108 | microbar, microbat, microbic, microdot, micromyx, micronor |
| fore- | 106 | fore(a), forearm, foredge, foreign, foreleg, foreman |
| auto- | 106 | autobus, autocue, automat, autopsy, autobahn, autocoid |
| semi- | 97 | seminal, seminar, semipro, semitic, semi-dry, semiarid |
| mid- | 79 | mid(a), mid-on, midair, midday, midden, middle |
| multi- | 69 | multiple, multiply, multiform, multilane, multiplex, multitude |
| Part | Words | For example |
| -y | 8542 | ably, achy, aery, airy, alky, ally |
| -ed | 4505 | acned, aided, aired, arced, armed, awned |
| -er | 4257 | adder, after, alder, alger, alter, amber |
| -ly | 3329 | amply, apply, aptly, badly, belly, bialy |
| -ing | 2876 | aching, acting, ageing, ailing, airing, arming |
| -al | 2173 | algal, appal, areal, argal, aural, axial |
| -tion | 2113 | auction, bastion, caption, caution, coition, diction |
| -ness | 2047 | aptness, badness, bigness, coyness, dimness, dryness |
| -ous | 971 | aurous, cerous, famous, humous, joyous, mucous |
| -ity | 953 | acuity, cavity, cecity, comity, dimity, enmity |
| -able | 888 | actable, addable, affable, amiable, capable, curable |
| -ism | 771 | ablism, ageism, autism, chrism, cubism, daoism |
| -ist | 729 | a-list, aorist, artist, assist, christ, cubist |
| -ise | 601 | advise, agnise, betise, braise, bruise, camise |
| -ize | 532 | agnize, assize, belize, iodize, ionize, resize |
| -ment | 459 | ailment, aliment, augment, clement, comment, element |
| -ish | 431 | aguish, banish, barish, bluish, boyish, danish |
| -less | 333 | ageless, aimless, airless, armless, artless, aweless |
| -age | 284 | ambage, anlage, borage, cowage, damage, degage |
| -ence | 280 | abience, absence, adience, cadence, defence, essence |
| -ful | 246 | armful, artful, bagful, binful, boxful, canful |
| -ance | 244 | advance, askance, balance, durance, enhance, finance |
| -sion | 200 | cession, elision, elusion, erosion, evasion, fission |
| -ship | 171 | airship, kinship, warship, worship, air-ship, amidship |
| -ible | 168 | addible, audible, delible, fusible, legible, risible |
| -est | 105 | arrest, attest, behest, detest, digest, divest |
| -ward | 38 | awkward, forward, froward, heyward, leeward, outward |
| -hood | 35 | boyhood, manhood, babyhood, girlhood, maidhood, serfhood |
| -dom | 29 | condom, fandom, random, seldom, wisdom, boredom |
| -wise | 25 | endwise, crabwise, edgewise, likewise, longwise, sidewise |