引语引语句子是four days later,如何变为间接引语?three days before 如何变直接引语?

首先,我很同意楼上的观点,只是最后的结论不敢苟同,there days before 是三天前,而there days later 是三天后,既然前面已经说了ago----before是相互转换的关系,所以there days before 应变为there days ago,如He said,“My sister was here three days ago,but she is not here now.” →He said that his sister had been there three days before,but she was not there then.
这是直接变为间接,所以间接变为直接就是这样的

直接引语变间接引语时， 指示代词、时间状语、地点状语等要作相应的变化。如：this/that→ these/those, now→then, today→that day, yesterday→the day before, last year→the year before, ago→before, here→there等。
所以four days later（直接）→ four day...

.ago表示“从现在起的若干时间以前”，意思是“距今……以前”，需和过去时或过去进行时连用。before泛指“从过去起的若干时间以前”，意思是 “距过去某时……以前”“与其……（毋宁）”，常和完成时连用，尤其在间接引语中，如：I visited him three days ago, but he had gone to Shanghai a week before．我三天前去访问他，但他已与那时...