以er, est结尾的单词变复数答:wide,nice,large,cute,fine,safe,late,able 变y为i加er:happy,heavy,early,drt,hungry,pretty,thirsty,busy,lucky,funny 双写辅音字母加er:hot,thin,big,red,fat,wet,sad 加most/more:(双音节)important, beautiful,useful,rapidly,expensive,quickly,difficultly,popular ...