许多词通过加词头(或称前缀，Prefixes)或词尾(或称后缀suffixes)来构成另一词类，称为派生。通过加词头或词尾构成的词称为派生词(derivatives)。
英语的词尾主要有下面这些：
1.构成名词的词尾(括号中词为例词):
-er (singer), -or (sailor), -ist (artist), -ee (employee), -es (hostess), -ian (musician), -ese (Japanese), -ant (contestant), -ism (heroism), -ess (happiness), -(a) tion (examination), -ment (movement), -on (decision), -ing (wedding), -ship (friendship), -ood (childhood), -age (shortage), -ure (failure), -dom (freedom), -ty (cruelty), -ity (reality), -y (discovery), -th (warmth), -al (arrival), -ance (reliance), -nce (difference), -ful (mouthful), -y (slavery), -eer (engineer)
2.构成形容词的词尾：
-ful (useful), -less (homeless), -ish (childish), -ive (active), -ous(famous), -able (eatable), -ible (responsible), -ic (poetic), -ant (pleasant), -ly (lively), -al (cultural), -y (rainy), -ent (dependent), -ary (imaginary), -some (tiresome), -ike (childlike), -en (wooden), -ate (fortunate), -an (Indian), -d (talented)
3.其他词尾：
-ize (modenize), -en (widen), -ify (simplify), -ate (originate), -y (slowly), -ward (backward), -wise (likewise), -teen (fourteen), -ty (forty), -th (ninth)
英语的词头有两类：
1.构成反义词的词头：
un-(unhappy), dis-(disagree), in-(informal), im-(impolite), ir(irregular), ill-(illegal), non-(non-conductor), de-(defrost)
2.有特定的意思的词头，如：
re-(retell), mis-(misspell), co-(co-exist), anti-(anti-tank), pro-(pro-French), counter-(counteract), over-(overdo), under-(under-paid), ex-(ex-wife), pre-(predict), post-(post-war), fore-(foresee), self-(self-made), inter-(interact), tele-(telephone), super-(superman), micro-(microwave), semi-(semi-circle), mini-(minibus), vice-(vice-chairman)
