1---monosyllabic words and a few -er to -ow at the end of the double syllable words, more in the -er, the most advanced in the -est;
(1)monosyllabic word
　　For example：small→smaller→smallest short→shorter→shortest
　　tall→taller→tallest great→greater→greatest
(2)disyllabic words
　　For example：clever→cleverer→cleverest narrow→narrower→narrowest
2---don't pronounce the monosyllabic word e at the end of the comparison, in this with -r, the most senior post in this -st;
For example：large→larger→largest nice→nicer→nicest able→abler→ablest
3---in the stressed closed syllables (ie: consonant + vowel + consonant), the first double write the end of the consonant letters, the comparison of the -er, the highest plus -est;
For example：big→bigger→biggest hot→hotter→hottest fat→fatter→fattest
4---to "consonant letter +y" at the end of the double syllable words, the y to I, plus -er, -est;
For example：easy→easier→easiest heavy→heavier→heaviest
　　 busy→busier→busiest happy→happier→happiest
5---other double syllable words and multi syllable words, comparison in the front plus more, the highest in the front plus most;
For example：beautiful→more beautiful→most beautiful different→more different→most different
　　 easily→more easily→most easily
Note: (1) superlatives before usually must use the definite article the, the former senior adverbs can not.
For example：The Sahara is the biggest desert in the world.
(2) the adjective most does not have a the in front of it, does not represent the highest level of meaning, only means "very".
For example：It is a most important problem.=It is a very important problem.
6---there are a few comparative adjectives and adverbs and the most senior is irregular, must be memorized.
For example：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