Question

宾语从句的主句如果不是一般现在时 过去时 从句应该用什么时态?例如主句是现在完成时从句用什么时态？谢谢

Answer 1

主句是一般现在时，从句什么时态都行
eg: He says that he is reading a book now.
主句是一般过去时，从句用过去范畴的时态
eg：He said that he would work hard
eg:They said the had been to France
这两个我举的例子从句一个用的过去将来时。一个用的过去完成时。
主句一般过去时，但是从句是客观的真理，或者自然现象，还是一般现在时
这个要注意，给你举个例子
eg：The students asked me if the earth goes round the sun.
这是客观真理。也是自然现象。这里的从句说的是地球围绕太阳转，这是永恒的真理，也是自然的现象，所以是一般现在时。

其他的主句和从句中间的时态关系须看具体情况。还是给你举几个例子
eg: My mother told me the cat had been fed by him.
eg：She said that she had taken it home with her
例子我也不多举了。希望帮助到你，祝学习进步

Answer 2

主句是过去式或过去完成时（与过去有关），从句一定要用过去时的相关时态（客观真理除外）
除了这个情况，从句的时态不受主句影响，应该看具体情况。

Answer 3

简单举四个例子
I know you are right.
I knew you were right.
I have known you are right.
I had known you were right.
补：讲一个大多数同学忽略的事实，现在完成时属于现在时，过去完成时属于过去时，还是举例子I couldn't remember where I --A----yesteday.A,went B have gone 明白前面所讲现在完成时属于现在时的同学肯定不会问为什么不选B了。