While young,the little girl could play the guitar very well

题目

While young,the little girl could play the guitar very well
为什么while 后要用young,用法是什么?

答案

这里省略了主语和谓语,还原就是
while she is young,the little girl could paly the guitar very well.
当while后面的be后的内容与girl形成修饰关系时,she is可以省略