She looked out into the street and saw the thief ____ by pliceman

问题描述:

She looked out into the street and saw the thief ____ by pliceman
请仔细讲讲,

caught saw为动词,the thief 为saw的宾语,caught 过去分词作宾语补足语,saw the thief caught by pliceman看到那个贼被警察抓住不是被动么?作宾语补足语时,用过去分词即可