形容词的比较级和最高级有两种形式：一，规则形式；二，不规则形式（指具有比较意思，但不用规则句型。）；

一，规则形式有：

1，单音节形容词和多音节形容词比较级的构成；S（主语）+be+ adj.-er / more + adj.（原形）than +S. 如：（1）Tom is taller than his sister. （2）Wang lin is more outgoing than his brother.

2, 单音节形容词和多音节形容词最高级的构成：S+be+the +adj-est / most + adj.(原形) + of / in ...

如：（1）Lili is the fattest in her class.（2）Mary is the most beautiful in her family.

二、不规则的比较级，如：He likes summer best.等等。