<h3>a knife</h3> <h3>two knives 规则以f，fe结尾的去掉f，fe，加ves</h3> <h3>a calf</h3> <h3>two calves</h3> <h3>a wolf</h3> <h3>two wolves</h3> <h3>a handkerchief</h3> <h3>three handkerchiefs or handkerchieves 有的名词，两种变化都可以</h3> <h3>a scarf</h3> <h3>nine scarfs or scarves</h3> <h3>a roof</h3> <h3>some roofs 有的名词很特殊，虽然是f结尾的，但还是直接加s</h3> <h3>a textbook</h3> <h3>four textbooks 规则一般是直接加s</h3> <h3>a pair of scissors</h3> <h3>two pairs of scissors 可数名词可以量化，单复变化在量词上变化。</h3> <h3>a pair of glasses</h3> <h3>two pairs of glasses</h3> <h3>a bottle of glue</h3> <h3>two bottles of glue 不可数名词也可以量化，单复数变化由量词来完成</h3> <h3>a box</h3> <h3>six boxes 规则 以s、x、o，ch、sh结尾的加es</h3> <h3>a bus</h3> <h3>some buses</h3> <h3>a toothbrush</h3> <h3>five toothbrushes</h3> <h3>a watch</h3> <h3>five watches</h3> <h3>a tomato</h3> <h3>some tomatoes</h3> <h3>a potato</h3> <h3>some potatoes</h3> <h3>a candy</h3> <h3>eight candies 规则以y结尾的前面的字母是辅音字母，则去掉y，变i，加es。</h3> <h3>a butterfly</h3> <h3>nine butterflies</h3>