下列词加es：1) s/x/ch/sh结尾的词加es 如：class,box,watch,brush,fox,match,dish,glass,2）“辅音+y”结尾的词,y改为i后,加es 如：city,country,study,3)下列o结尾的词加es:tomato,potato,hero,zero,mango,negro,....