25人教版四年级英语下册第四单元:At the farm同步教学 可数名词变复数的规则: 1、一般情况下,在单数名词词尾加“s”.如: cat? cats dog? dogs book? books ruler? rulers 2、在以s, ss ,x , sh , ch 结尾的名词后面加“es”,如: box? boxes peach? peaches bus? buses class? classes 3、在以o结尾的单词后面加“es”,如: tomato? tomatoes potato? potatoes