有规则的有：
(1)直接在名词后加s
如orangeoranges；photophotos；
(2)以x，s，sh，ch结尾的加es
如：boxboxes；glassglasses；waitresswaitresses；watchwatches；peach--peaches
(3)以辅音字母加y结尾的改y为i加es
如：studystudies；librarylibraries；hobbyhobbies；familyfamilies；
(4)以f，fe结尾的改f，fe为v＋es如：knifeknives；thiefthieves（注：以o结尾的我们学过的只有mango加es，mangomangoes其余加s，）
不规则的有：
manmen；womanwomen；peoplepeople；childchildren