Iheard him go down the stairs. 

I heard him going down the stair. 

I heard himwent down the stairs.

–

I saw her go dwon the stairs   stairs. 

I saw her going down the stairs.  

–

I sawthe book lying on the table. (not I saw the book lie …)

I couldsee Jack getting on thebus. (not I could see Jack get …)

Isaw her throwing stonesat the other children.

被动状态的两个例子

He was never heardto say ‘thankyou’ in his life. (not He was never heard say …)

I heard my namerepeated.