是她的两倍英文

a is as tiwce as b. a is twifold as b. b is a half of a. etc.

a is two times more than ba equals to two bs

my strength is twice as big as hers.这里后面的“她的”要用名词性物主代词：hers,在内容上相当于her strength.

比如我的力气是她的两倍大。For example, my strength is twice as big as her.