常用词根：
　　ann = year: anniversary, annual
　　audi = hearing: audience, audible
　　auto = self: automation, autobiography
　　bio=life: biology, biography
　　capit = head: capital, decapitate
　　ced/cess = go: process, unprecedented
　　cur =run, move: occurrence, incur，current
　　chron = time: chronic (长期的，慢性的) ,
　　chronology (年代学，年表), synchronal （同时，
　　同期）
　　cide = kill: suicide, insecticide, bactericide
　　confid = trust: confide, confidant(密友),
　　confidential （恪守秘密的），
　　confidence
　　cred = trust: credit, credible,
　　dic = say: indicate, dictate (读出，口授)
　　duc(t) = lead: introduce, conduct
　　equ = same: equal, equality, equation (等式)
　　fact = make: manufacacture, factory - 5 -
　
　　frag = break: fragile, fragment
　　gen = produce: generate, genetics
　　ject = throw: eject, reject, project
　　mit = send: emit, vomit
　　port = carry: porter, export, import,
　　transport
　　simil = like: similarity, simile
　　spect = see: inspect, expect
　　tract = draw: tractor, attract, distract
　　vid/vis = see: vision, invisible
　　常用前缀：
　　en-: enable, encourage, enforce, entitle, enlarge, enliven, enrage, enrich, enslave, ensure, entrust, encage
　　trans-: transform, transition, transport, transmit, translate, transplant,
　　post-: postwar, postgraduate, posterior
　　under-: underground, underway, undergraduate, undercharge, underestimate, underfunded undernourished, underprivileged, undersell, understate, undervalue,
　　de-: devalue, defrost, dewater, dehydrate, defame, deface, deform, degenerate, degrade, denounce (announce), deselect, detach (attach), detract (attract),
　　tele-: telegram, telephone, telescope, television
　　semi-: semicircle, semiautomatic, semidetached, semi-skilled, semitropical (subtropical)
　　bi-: bicycle, bilateral, bilingual,
　　tri-: tricycle, triangle, trisect, triple
　　multi-: multiple, multiply, multitude, multilingual, multilateral, multimedia, multinational
　　mono-: monologue, monotonous, monopoly, monopolize, monlingual
　　sub-: submarine, subway, subcontinent, subconscious,
　　il-: illogical, illegal, illiterate,
　　ir-: irregular, irrelevant, irresistible, irresolute, irresponsible,
　　im-: impossible, impolite, impartial, impatient, impossible, impiety, implausible, impotent, impractical, imprecise impure, imbalance, immature, immeasurable, immobile, immodest, immoderate, immoral, immortal,
　　ex-: export (import), exclude (include), , expose, exhale (inhale)exterior (interior), external (internal) explicit (implicit)
　　co-: cooperate, coexist, coeducation, coincidence (coincide),
　　后缀：
　　-en: deepen, widen, broaden, lighten, weaken, fasten, harden, loosen, lengthen, threaten
　　-ify: clarify, identify, justify, qualify, specify
　　-ize: characterize, specialize, industrialize, civilize, realize, modernize, organize