英语中表达倍数的常用方法有以下几种：
倍数 + the size/weight/height/depth/width/length/… + of…
例如：The Amazon rainforest is more than half the size of China.
倍数 + as + 形容词/副词原级 + as…
例如：Cats sleep twice as much as people.
倍数 + 形容词/副词比较级 + than…
例如：The new park is 10 times larger than the old one.
倍数 + what从句
例如：He makes five times what he can earn back home.
倍数 + as…as…
例如：I am twice as old as he.
倍数 + 比较级 + than…
例如：This hall is five times bigger than our classroom.
倍数 + the size/length/width/height/age等名词 + of…
例如：The earth is 49 times the size of the moon.
动词 + 倍数
例如：The car runs twice faster than that truck.
动词 + by + 数词/百分比/倍数
例如：He increased the production by three times.
这些表达方法可以帮助你更准确地描述数量上的倍数关系。根据具体的语境和需要，可以选择合适的表达方式来传达信息。