He can run fast.划一条横线在fast上,特殊疑问句怎么变

He can run fast.划一条横线在fast上,特殊疑问句怎么变

应该是：How can he run -他跑起来怎么样?
如果是How fast can he run?那么意思就是：他跑的有多快.对应的回答应该是 He runs liks a cougar 之类 描述其速度的句子.

变成特殊疑问句就是How fast can he run？