什么叫单数名词和复数名词详细一点答:calf,half ,knife,leaf,life,loaf,self,sheaf,shelf,thief,wife,wolf 等.如:wife-wives,wolf-wolves,calf-calves.6.以下几个名词scarf,wharf,hoof,handkerchief等的复数形式,可先将-f或-fe改成-v,再加-es;也可直接加-s ,即scarfs或scarves,wharfs或wharves,hoofs或hooves,handkerchiefs或hand...