大凡英语学习者，都会觉得单词难记。因此很多英语学习先行者总结出不少行之有效的记忆单词方法，其中一种方法就是利用构词法记单词。利用构词法记单词确实是一种很有效的方法，符合英语词汇的构成规律。常见的构词法有三种，其中一种叫派生法。所谓派生法，就是在词的前面加上前缀或在词的后面加上后缀构成另一个词的方法。本文针对初中所学的前缀后缀，进行归类，来个大汇总，方便初中生尤其是即将参加中考的学子们记忆，并且通过例句讲解，帮助大家掌握这些词的用法。这是本文区别于其它很多同类文章所不同的地方，严格从考纲出发，所列举的词100%是初中所学，是中考考纲所要求掌握的，希望我的付出可以帮到更多的同学。
一、前缀的作用及所学的前缀
前缀用在词根前面以改变词的意义，一般不改变词性。初中所学的前缀有：
一）否定前缀
1. un- :unhappy,unusual,unfair,unlike,unfriendly,uncomfortable,uncrowded,uneasy,unexpected,unlucky,unbelievable,unable，unforgettable。
2. im-:impolite,impossible。
3. in-:inexpensive,incorrect,informal。
4. dis-:dislike,disappointed,discover,discourage,dishonest,disappear,disbelief，disadvantage,disabled。
5. ir-：irregular。
二）其它前缀
1. re-(表示再，又）：review,recycle,return,reuse,reusable,research。
2. inter-(表示在。。。。。。之间，相互）：interview,internet,international。
3. under-（表示低于）：underwear,underground。
4. bi-（表示两）：bicycle。
如I don’t feel happy也可以说成I feel unhappy。上面的unlike是介词，而dislike是动词，在使用时必须引起注意。另外，含有否定前缀的词用在反义疑问句中，后面简短的一般疑问句照样要用否定的，如:
1. That’s impossible,isn’t it?
2. He feels unlucky,doesn’t he?
二、后缀的作用及所学的后缀
后缀用在词根后面以改变词性。初中所学的后缀有：
一）动词变成名词
在一个动词后面加上某一个后缀，使之变为名词。
1).动词+er/or/ist/ress变成名词（表示动作的执行者）
A.teach-teacher,work-worker,read-reader,think-thinker,perform-performer,wait-waiter,sing-singer,play-player,cook-cooker,record-recorder,keep-keeper,listen-listener,farm-farmer,climb-climber，lead-leader,speak-speaker,report-reporter,clean-cleaner,help-helper。
B.write-writer,drive-driver,dance-dancer,ride-rider,rule-ruler,manage-manager,make-maker。
C.run-runner,win-winner,travel-travel（l）er。
D.visit-visitor,act-actor,invent-inventor,compete-competitor,translate-translator,direct-director。
E.tour-tourist。
F.wait-waitress,act-actress。
2).动词+tion变成名词
act-action,suggest-suggestion,communicate-communication,invite-invitation,pollute-pollution,compete-competition,predict-prediction,invent-invention,prepare-preparation,protect-protection,celebrate-celebration,direct-direction,educate-education,examine-examination,inspire-inspiration,introduce-introduction,produce-production,graduate-graduation,pronounce-pronunciation。
3) .动词+ing变成名词
draw-drawing,paint-painting,build-building,say-saying,cross-crossing,happen-happening,end-ending,mean-meaning,feel-feeling,begin-beginning,open-opening。
4) .动词+ment变成名词
agree-agreement,disagree-disagreement,develop-development,improve-improvement,encourage-encouragement,punish-punishment,achieve-achievement,manage-management。
5）.动词+ance变成名词
appear-appearance,disappear-disappearance。
6）.动词+sion变成名词
express-expression,discuss-discussion,decide-decision。
在句子中，如果作主语、宾语、表语，就要把动词改为名词。我们来看看，
用括号内所给词的适当形式填空：
1. He is a basketball_______(play).
2. Thank you for your_________(invite).
3. The teacher is pleased with his ________(improve)in English.
二）名词变成形容词
在一个名词后面加上某一个后缀，使之变为形容词。
1）.名词+ful变成形容词
thank-thankful,help-helpful,care-careful,use-useful,hope-hopeful,beauty-beautiful,wonder-wonderful,pain-painful,harm-harmful,success-successful,truth-truthful。
2）.名词+less变成形容词
help-helpless，hope-hopeless,use-useless,care-careless,harm-harmless。
3）.名词+y变成形容词
rain-rainy,wind-windy,snow-snowy,sun-sunny,fog-foggy,ice-icy,health-healthy,luck-lucky,noise-noisy,sleep-sleepy,thirst-thirsty,hunger-hungry。
4）.名词+ly变成形容词
week-weekly,love-lovely,friend-friendly,live-lively。
5）.名词+al变成形容词
person-personal,music-musical,tradition-traditional,center-central,nature-natural,culture-cultural,digit-digital,accident-accidental,education-educational,profession-professional,nation-national,medicine-medical,environment-environmental。
6）.名词+ous变成形容词
danger-dangerous,humor-humorous,fame-famous，mystery-mysterious。
7）.名词+ern变成形容词
east-eastern,west-western,south-southern,north-northern,southeast-southeastern。
8）.名词+en变成形容词
wood-wooden,wool-woolen,gold-golden。
9）.名词+ish变成形容词
fool-foolish,self-selfish。
10）.名词以ce结尾，把ce改为t变成形容词
silence-silent,patience-patient,confidence-confident,importance-important,convenience-convenient。
在句子中，如果作表语、定语或宾补时，很可能要把名词变成形容词。大家再看：
1. Look after yourself and keep_______(health).
2. They are talking about_____(healthy)problem.
3. You should eat______(health)food.
4. Playing basketball keeps me_____(health).
5. We should do more sport and eat______(health).
三）动词变成形容词
动词的现在分词、过去分词可作形容词，或在动词后加上某些后缀也可变成形容词。
1) .动词+ing（即现在分词）变成形容词
move-moving,care-caring,understand-understanding,burn-burning,freeze-freezing,fascinate-fascinating,embarrass-embarrassing,surprise-surprising,bore-boring,tire-tiring,excite-exciting,interest-interesting,disappoint-disappointing,frighten-frightening，boil-boiling。
2）.动词+ed（即过去分词）变成形容词
move-moved,burn-burned（或burnt）,freeze-frozen,embarrass-embarrassed,disappoint-disappointed,
surprise-surprised,bore-bored,tire-tired,worry-worried,excite-excited,interest-interested,frighten-frightened,boil-boiled。
3）.动词+able变成形容词
understand-understandable,forget-forgettable,enjoy-enjoyable,comfort-comfortable,value-valuable,believe-believable。
动词和形容词在句子中的作用决然不同，在使用时要很好根据实际情况作出变化,当然也要很好区分现在分词与过去分词所作的形容词，现在分词表示主动或正在进行，多数形容事物；过去分词表示被动或已经完成，多数形容人。如；
1. I am___(bore)with the____(bore)job.
2. He found the news______(excite).
3. Only when something is lost do we find it______(value).
四）形容词变成副词
除了一些形容词、副词同形的词如early/late/fast/high/far/hard等以外，大多数形容词后面加上ly变成副词，不过有些要作改变，注意不同的变化情况。
1).careful-carefully,real-really,wide-widely,wise-wisely,polite-politely,loud-loudly,gradual-gradually,general-generally,most-mostly,cheap-cheaply,special-specially,certain-certainly,sudden-suddenly,recent-recently,different-differently,complete-completely,beautiful-beautifully,total-totally,slow-slowly,quick-quickly。
2).happy-happily,easy-easily,heavy-heavily,angry-angrily,lucky-luckily,healthy-healthily,noisy-noisily。
3).simple-simply，gentle-gently,possible-possibly,probable-probably,comfortable-comfortably,terrible-terribly。
4).true-truly。
形容词作表语、定语、宾补，而副词作状语。试对比：
1. That thing made（使） me happy.（形容词作宾补）
2. They are making（制作） cards happily.（副词作状语）
3. We live a happy life.（形容词作定语）
4. She seems very happy.(形容词作表语）
五）形容词变成名词
形容词后面加上后缀ness/th/ity等可变回名词。
1) .good-goodness,kind-kindness,ill-illness,sick-sickness,sad-sadness,shy-shyness,fair-fairness,busy-business,careful-carefulness,careless-carelessness。
2) .warm-warmth,long-length,wide-width,true-truth,young-youth。
3) .able-ability,active-activity,creative-creativity,popular-popularity。
形容词和名词作用不同，在使用时要多加注意。我们来看这两道选择题：
1.This time he failed the exam because of his_____.
A. care B.carefulness C. careless D. carelessness
2.She helped to look after a/an____man.
A.ill B. sick C. illness D.sickness
以上对现行初中课本（人教版）所出现的前缀后缀进行了总结，并对其用法进行了很好的剖析，对初中生的英语学习应该有一定的帮助。
