4.9 比较级形容词或副词 + than
 
    You are taller than I.
    They lights in your room are as bright as those in mine.

注意:
1)要避免重复使用比较级。
   (错) He is more cleverer than his brother.
   (对) He is more clever than his brother.
   (对) He is clever than his brother.

2)要避免将主语含在比较对象中。
   (错) China is larger that any country in Asia.
   (对) China is larger than any other countries in Asia.

3)要注意对应句型,遵循前后一致的原则。
    The population of Shanghai is larger than that of Beijing.
    It is easier to make a plan than to carry it out.

4)要注意冠词的使用,后有名词的时候,前面才有可能有名词。
  比较:Which is large, Canada or Australia?
     Which is the larger country, Canada or Australia?
     She is taller than her two sisters.
     She is the taller of the two sisters.