宾语从句当主句是过去式从句怎么变

当主句为现在时或将来时,宾语从句的时态一般不受主句的时态所影响.
当主句为过去时
①从句用一般过去时或过去进行时表示与主句谓语动词动作同时发生
I only knew he was studying in a western country,but I didn’t know what country he was in.
我只知道他当时在西方的一个国家读书,可不知道是哪个国家.
He asked me if I was reading the story The Old Man and the Sea when he was in.
他问我他进来的时候我是否正在读.
②从句过去完成时表示该动作发生在主句谓语动作之前
He told me that he had told Mary about the meeting already.
他告诉我他已经把有关会议的事情告诉的了Mary.
③从句谓语用过去将来时表示该动作发生在主句谓语动作之后
The reporter asked if the government would take necessary measures to put down the to-do.
记者问*是否会采取必要的措施镇压*.
如果从句是一个客观真理,那么从句的时态不根据主句的时态而变化
The teacher said that the moon goes around the earth yesterday.
老师昨天说月亮绕着地球转.
当宾语从句的引导词是who,which,what,when,where,how,why等表疑问时,不能按正常语序安排,经常将这类引导词置于句首
Who do you think the public might choose as their favorite singer this year?
你认为今年公众会选谁为他们最喜欢的歌手.