Do you hear my mother walking downstairs?为什么用该walking?

Do you hear my mother walking downstairs?为什么用该walking?
Do you hear my mother walking downstairs?为什么用该walking?

Do you hear my mother walking downstairs?为什么用该walking?
因为该句用了hear这个感官动词.
hear有两种搭配,分别是hear to do 和hear doing.
hear doing强调此人正在做某事,强调动作.
虽然有do,但是因为有hear,所以应为walking.