为什么class的复数形式为classes,不是以s,sh ,ch,x等结尾的词的...答:1.最普遍直接+S:desk-desks,pen-pens.2.以s,x,ch,sh结尾的名词+es.bus-buses watch-watches.3.以辅音字母+y结尾的名词把yi+es:baby-babies country-countries.4.以f或fe,如:thief life wife half等,要把f或fe变成v+es.而特殊要注意的safe roof belief gulf chief等词就直接加S.5.以O...