英语构词法中的派生法派生法：在词根加前缀或在词根后面加后缀构成一个与原单词意义相近或截然相反的新词叫作派生法。
一、前缀前缀一般改变单词的意义，不改变词性（除少数前缀外）；后缀一般改变词类，而不引起词义的变化。
(1) 表示否定意义的前缀常用的有： dis-, il-, im-, in-, ir-,mis-, non-, un- 。
disable disadvantage disagree disappeardisapprove disclose discolour disconnectdiscontinuous discontinue discount discouragedisorderillegal impossible inaccurate inactiveinadaptable inapplicable inconstant inconvenientincredible incurable independent ineffectiveinformal invisible irregular irremovableirrespective irresponsiblemisfortune misguide midinterpret misleadmisread mistrust misunderstand misusenonmetal noncooperation noninvolvementunable unacceptable unaware unbalanceunbreakable uncertain unchangeableuncomfortable undecided unemployedundetermined undeveloped unearth uneconomicalunfold unpack untie(2) 表示其他意义的前缀常用的有：a.前缀antianti-fascist anti-gas anti-imperialistanti-Japanese Warb.前缀autoautobiography autographyc.前缀bi-bicentury bilinguald.前缀coco-operation coauthor coheire.前缀dedeform degrade devaluef.前缀en- emenable encourage endangerenlarge enrich embitterg. 前缀exex-soldier ex-girlfriend ex-wifeh.前缀mid-midday midnight midterm mid-agedi.前缀multi-multiform multilingual multimedia multipurposej. 21. 前缀over-overcrowded overwork overload overproduceoverlook overcomek. 22.前缀pre-prewar prehistoric prepay preconditionl.前缀re-rewrite review recyclem.前缀vice-vice-chairman vice-governor vice-premier vice-president二、后缀后缀通常会改变单词的词性，构成意义相近的其他词性；少数后缀还会改变词义，变为与原来词义相反的新词。
(1)构成名词的后缀常用的有：a、后缀-age，构成抽象名词marriage percentage shortage storageb.后缀al- 构成抽象名词arrival refusal approval survivalproposal removalc.后缀–an ，-ian “人”从事……职业者”，构成名词。
Italian librarian magician vegetarianmusician politician techniciand.后缀-ance，-ence，构成名词.appearance allowance existence presenceperformance ignorance influence intelligenceevidence diligence guidancepreference significancee.后缀-dom 构成名词kingdom freedomf、后缀-ee，-eer，-er，-or，构成表人的名词beginner competitor conductor director employee engineer examinee intervieweetailor volunteerg.后缀-ess 构成表“雌性”的名词actress goddess hostess waitressh、后缀-ful 构成表“容量单位”名词a basketful of a handful of mouthful spoonfuli.后缀-ics 构成学科名词：gymnastics physics politics mathematicsj、后缀-ism ，构成名词Buddhism extremism imperialism terrorismpatriotism socialism tourismk、后缀-ist 构成名词。
bioiogist chemist economist specialist extremist geologist physicistl. 后缀-ment 构成抽象名词advertisement agreement amusement appointment argument arrangement development embarrassment equipmentestablishment improvement judgment requirement treatment m.后缀-ness 构成抽象名词：coolness correctness dampnessm. 后缀-sion 构成抽象名词：aggression comparison conclusion expression invasion permission tensionn. 后缀-th 构成抽象名词birth depth length strength warmthwidth youth0. 后缀-tion 构成动作名词或抽象名词application celebration classification creation congratulation consideration consolidation descriptionp.后缀–ure，构成抽象名词failure mixtureq. 以-ity或ty结尾，构成抽象名词ability curiosity electricity equalityidentity majority prosperity society(2) 构成动词的后缀常用的有：a.后缀-en ，形容词后的-en，构成及物动词。
名词后的-en 构成形容词brighten deepen flatten frighten loosen sharpen strengthen widenwooden woolenb.后缀–ize，构成及物动词apologize analyse categorizeorganize realize(3) 构成形容词的后缀常用的有：a.后缀-ableacceptable adjustable admirable avoidable unbelievable comparable endurable incredible reasonable recycleable respectablevaluable visibleb、后缀–al 构成形容词environmental grammatical natural occasional original operational personal politicalpractical professional traditional universalc、后缀-ant/-ent，构成形容词distant important patient convenient permanent urgent violentservantd、后缀-ed 构成形容词：astonished delighted experienced learnedskilled unitede.后缀-ful，构成形容词careful doubtful dreadful regretful resourcefulforgetful frightful hopeful respectful tearfulf. 后缀–ic，构成形容词basic economic enthusiastic electric energeticheroic historic systematicg. 后缀–ing 构成名词或形容词amusing astonishing flaming greetingmisunderstanding promising satisfying suffering trainingh. 后缀-ish 构成形容词：feverish foolish Swedish Spanishi. 后缀–ive，构成形容词aggressive attractive instructivepersuasive predictivej.后缀–less，构成否定形容词careless hopeless helplessk、后缀-ly 构成的形容costly daily friendly lively lonely lovelyl. 后缀–ous 或-ious 构成形容词：adventurous ambitious consciousenvious humorous industriousmountainous religious variousm.后缀-y 构成的形容词或名词bloody bravery difficulty honesty icy loyalty(4) 构成副词的常用后缀有：a.后缀-ly或–ingly 构成的副词accurately constantly effectivelyfrequently generally indirectly三、经典例题2. The soldier died for saving the child，so his________ is heavier than Mount Tai.A. dieB. deadC. diedD. death5.The three- ________chair isn’t suitable for a young child. He may fall off.A. leggingB. leggedC. legsD. leged7.When the teacher praised him for working out the maths problem，Jack looked________about at his classmates.A. proudB. proudlyC. prideD. pridely8.To everyone’s ________，the girl finished the job quite well.A. satisfiedB. satisfactoryC. satisfyingD. satisfaction10. No one should enter the spot without the________of the police.A. permitB. permissionC. permittingD. permittence四、专项训练1. You must come with us to the police ________.Our head is waiting for you.A. headquartersB. headlineC. headmasterD. headache2.Letting that animal escape was no accident；you did it ________.A. intendB. intentionC. intentionallyD. intentional3. The shop owner welcomed all the guests with a________smile.A. practiceB. practiseC. practicalD. practiced4. My TV is out of order. Can you tell me what is the________news about Iraq War?A. latelyB. latestC. laterD. latter5. The Great Wall is more than 6000 li in ________.A. longerB. lengthC. longD. longing6.To my ________，I passed the exam easily.A. joyB. joyfulC. joylessD. joyness7. Canada is mainly an________country.A. English-speakingB. speak-EnglishC. spoken-EnglishD. English-spoken8. The necklace that she lost is very expensive. It’s of great ________.A. valuableB. valueC. valuelessD. unvaluable9.The letter “b” in the word “doubt” is________.A. soundB. silentC. silenceD. sounded10. What you said sounded________ but in fact it was untrue.A. reasonableB. reasonfulC. reasonlessD. unreason11. We have to learn ________technology from other countries.A. advanceB. advancingC. advantageD. advanced12.You’d better give up smoking if you want to keep ________.A. healthB. healthyC. healthilyD. healthier13.________ speaking，I didn’t do it on purpose.A. HonestlyB. HonestC. HonestyD. Dishonest五、课堂总结1、否定前缀、其他前缀2、名词、形容词、副词、动词常用后缀。