先观察下面几组词汇：
tall taller
short shorter
big bigger
important more important
obvious more obvious
大家从上面能发现什么规律呢?
1.形容词的比较级一般是在原型后加-er, 比如高tall, 更高taller
2.像big这样的重读闭音节，变成比较级时必须先双写最后一个字母再加er
3.像important, obvious这样的多音节词，其比较级是在单词前加more, 比如明显的obvious, 更明显的more obvious.
注意：比较级一般是两者之间的比较，也可是同一事物不同时期的比较，但若涉及三者或三者以上的`比较，则要用最高级。
1. She is becoming more and more beautiful. 她变得越来越漂亮了。
2. He is getting taller and taller. 他变得越来越高了。
3. He is older than me. 他比我大。
4. He is much older than me. 他比我大多了。
5. Our school is two times larger than theirs. 我们的学校比她们的学校大两倍。
