1．一般单音节词和少数以-er,-ow结尾的双音节词,比较级在后面加-er,最高级在后面加-est； （1）单音节词 如：small→smaller→smallest short→shorter→shortest tall→taller→tallest great→greater→greatest （2）双音节词 如：clever→cleverer→cleverest narrow→narrower→narrowest 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； 如：large→larger→largest nice→nicer→nicest able→abler→ablest 3．在重读闭音节（即：辅音＋元音＋辅音）中,先双写末尾的辅音字母,比较级加-er,最高级加-est； 如：big→bigger→biggest hot→hotter→hottest fat→fatter→fattest 4．以“辅音字母＋y”结尾的双音节词,把y改为i,比较级加-er,最高级加-est； 如：easy→easier→easiest heavy→heavier→heaviest busy→busier→busiest happy→happier→happiest 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； 如：beautiful→more beautiful→most beautiful different→more different→most different easily→more easily→most easily 注意：（1）形容词最高级前通常必须用定冠词 the,副词最高级前可不用.例句：The Sahara is the biggest desert in the world.（2） 形容词most前面没有the,不表示最高级的含义,只表示"非常".It is a most important problem.=It is a very important problem.6．有少数形容词、副词的比较级和最高级是不规则的,必须熟记.如：good→better→best well→better→best bad→worse→worst ill→worse→worst old→older/elder→oldest/eldest many/much→more→most little→less→least far →further/farther→ furthest/farthest