Wǒ shuō tā le, xià zhōu lái.
False: 我说她了,下周来。
Wǒ ɡàosu tā le, xià zhōu lái.
True: 我告诉她了,下周来。
可以理解为谓语动词后边有两个宾语,一个指人(“他”),一个是一件事(“下星期学弟第三本书”)。应该把“说”改为“告诉”。
The predicate verb here may be considered to have two objects, with one referring to the person(他);The other referring to the event(下周来). We replac 说 by 告诉.