1. 宾语从句是用一个句子来充当宾语。如：I know she is a girl. 宾语 She is a girl是一个完整的句子。2. 宾语补足语是用一个词或者短语来充当。它和宾语有主谓关系。如：I know the boy playing football.用宾补playing football 来补充说明宾语the boy 做什么。
