1、形容词表示某一事物或人的特征，副词表示某一动作的特征。
形容词和副词有三种形式：原形、比较级、最高级。比较级：+er 最高级：the …+est
两个重要特征：as……as中间一定用原形，than的前面一定要+er。
2、形容词、副词比较级的规则变化如下：
（1）一般直接+er。如：tall - taller, fast - faster 单音节词如果以-e结尾，只加-r。如：late - later
（2）重读闭音节词如末尾只有一个辅音字母，须双写这个字母，再加-er。如：big - bigger, fat - fatter
（3）以辅音字母加-y结尾的词，变y为i，再加-er。如：heavy - heavier, early - earlier
（4）双音节和多音节词的比较级应在原级前加more构成。如：beautiful - more beautiful, careful - more careful, quietly - more quietly, interesting - more interesting
（5）有些不规则变化的，须逐一加以记忆。如：good/well – better, bad/ill – worse, many/much – more, far – farther/further, old – older/elder…
练一练：
1、写出下列形容词、副词的比较级。
big good long tall old
short thin heavy young fat
light strong high far low
early late well fast slow
2、用括号内所给单词的适当形式填空。
1) I can swim as _______ (fast) as the fish, I think.
2) Look! His hands are _______ (big) than mine.
3) I think you do these things_______ (well) than your classmates.
4) Whose bag is _______ (heavy), yours or mine?
5) Does Jim run as _______（slow) as David? Yes, but Mike runs_______ (slow) than them.
6) You have seven books, but I have _______ (many) than you. I have ten.
7) I jump _______ (far) than some of the boys in my class.
8) I’m very_______ (thin), but she’s _______ (thin) than me.
9) It gets _______and_______ (warm) when spring comes here.
