句子1是正在进行时be doing 结构其中the boy 是主语was crying 是谓语意思:这个男孩正在哭 句子2是现在完成进行时has/have been diong意思为一直.表示动作的起点发生在过去一直持续到现在可能继续延续,其中the pretty girl 是主语(形容词+名词形式)has been doing 是谓语 since 引导时间状语.意思:这个漂亮的女孩自从进屋后就一直在滔滔不绝的讲话
"The boy" is subject."Was crying" is predict. "The pretty girl" is subject."Has been talking" is predict. ."since she came into the house " is adverbial of time..