have had或had had 的用法？

Question

She has had three children in the past five years.和She had three children in the past five years.有什么区别？

Answer 1

你的第一个句子是对的。在过去的五年里，是现在完成时的标志。第二个句子是错的。第二个句子这种时态与时间状语不一致。。

Answer 2

have had是现在完成时，如第一句。
第二句是一般过去时。

Answer 3

前者为现在完成时，表示做的一件事对现在的影响；had had为过去完成时，表示过去的过去。

Answer 4

have had 现在完成时
had had 过去完成时

Answer 5

have had 是have 现在完成时的结构
had had 是have 的过去完成时结构。
影响
过去完成时是指在过去某个时间或动作之前发生的动作