1.比较级在后面加-er,最高级在后面加-est short-shorter-shortest
2.以不发音e结尾的单音节词,比较在原级后加-r,最高级在原级后加-st;
large-larger-largest
3.在重读闭音节,双写末尾的辅音字母,比较级加-er,最高级加-est
big-bigger-biggest
4.辅音字母+y结尾, 把y改为i,比较级加-er,最高级加-est
heavy-heavier-heaviest
5.其他双音节词和多音节词,比较级在前面加more,最高级在前面加most
beautiful-more beautiful-most beautiful