affixes
【正确答案】：Affixesaremorphemesattachedtotherootorstem.Theyarealwaysboundmorphemes.Accordingtotheirfunction,affixesmaybeclassifiedintotwotypes:inflectionalaffixessuchas“?ing”,“?er”,“?est”,“?s”etc.,andderivationalaffixessuchas“be?”,“?en”,“dis”etc.Accordingtotheirposition,affixescanbeclassifiedintotwotypes:prefixessuchas“un?”,“im?”,“il”etc.,andsuffixessuchas“?ly”,“?hood”,and“?ness”etc.