宾语补语是用来补足宾语的意义,表明宾语的性状的.
Do you think him a good writer?
你认为他是个好作家吗?（think是动词him 是宾语,a good writer是宾语补语,补充说明宾语him的意义.）
又例
比较一下
Mr.Smith gave me a watch as my birthday present.
Mr.Smith gave (me) a watch as my birthday present.
及物动词gave 后的 me ,就是间接宾语,而离得远一点的 a watch 就是直观宾语.