一、两个原级的分句合并成含比较级的句子。如：

Kate is eleven years old. Emma is eight years old.

Kate is older than Emma.

Emma is younger than Kate.

Kate is three years older than Emma.

Emma is three years younger than Kate.

二、“not as/so + 原级 + as”结构可转化为比较级结构。如：

This movie is not as interesting as that one.

That movie is more interesting than this one.

Mike didn’t run so fast as Tom.

Tom ran faster than Mike.

Mike ran more slowly than Tom.

三、“not as/so + 原级 + as”结构可转化为“less + 原级（指少数双音节词和多音节词）+ than”结构。如：

This sport isn’t as popular as that one.

This sport is less popular than that one.

四、比较等级的句子中含有any, anyone, anything, other等时，可转换成含最高级的句子。如：

Shanghai is bigger than any other city in China.

Shanghai is the biggest city in China.

This book is newer than any of the others of all.

This book is the newest of all.

He walked faster than anyone else of the four.

He walked (the) fastest of the four.

五、含比较级的句子可用反义词改写。如：

This bottle is bigger than that one.

That bottle is smaller than this one.

六、like…better (than) 可转化为prefer…(to)结构。如：

Do you like sandwiches better?

Do you prefer sandwiches?

I like noodles better than dumplings.

I prefer noodles to dumplings.

七、like…best结构可改为含favourite的句子。如：

He likes badminton best.

Badminton is his favourite sport.

His favourite sport is badminton.