1. as（形容词 / 副词原级）as
表示A和B的程度相同
例如：Heis as tall as his brother. / He runs as quickly as Jim.
2. not as / so（形容词 / 副词原级）as
表示A不如B
例如：Thatgirl isnt as / so fat as Amy.
3. less + adj. / adv.原级 + than
表示没有adj. / adv.
例如：Sheis less beautiful than her sister.
He runs less quickly than Jim.