直接引语转变为间接引语,为什么这个时态不变有个例子 teacher asked tom,"why were you late again?" 转后为 teacher asked tom why he was late again.时态变化不是 一般过去时变过去完成时么?这个为什么不变?还有一个例子 father asked him,"when did you go to bed last night" 转后 father asked him when he went to bed the night before那什么时候是一般过去时,什么时候是过去完成时,有没有一个规律的?还是都可以?

第一个例子：间接引语中的谓语动词时态对比.
Sarah said to me,”I have two brothers.” 莎莎对我说：“我有两个弟弟.”
Sarah told me that she has two brothers.莎莎告诉我说她有两个弟弟.（说话才认为这情况是真实的）
Sarah told me that she had two brothers.莎拉告诉我说她有两个弟弟.（说话者对此没有什么把握）
第二个例子：间接引语中有明确的过去时间状语,仍可用一般过去时,不必改为过去完成时.
The girl said,"Iwas born in 1978."
→ The girl said that she was born in 1978.那女孩说她生于1978年.
She said,"My teacher was busy yesterday."
→ She said that her teacher was busy yesterday.她说她老师昨天很忙.那题的lastnight 就是属于这种情况!