Question

have done 和had done 怎么用 最好有讲解有题

Answer 1

1. have done是现在完成时，表示动作发生在过去一直延续到到现在为止。或许动作已完成，或许动作还在进行。如：
We have finished our task. 我们已经完成了任务。（强调动作已终止）
We have lived here for ten years. 1.我们在这里住了十年了。（表示动作终止。）
2. 我们已经在这里住了十年了。（我们现在仍住在这里。表 示动作仍在进行）=We have been living here for ten years.
2. had done 是过去完成时，表示过去的过去，指过去某一时间之前就已完成的动作。如：
We had finished it by the time they went back.
He told us that he had seen the film (two years before).
Last night, he had not come back by 12 o'clock.

Answer 2

have done是现在完成时表示到现在已完成的动作。 We have finished our task.
had done 是过去完成时表示在过去的过去就已完成的动作。We had finished our task by the time they went back.

Answer 3

had done 是过去完成时表示在过去的过去就已完成的动作, 句子中必定有表示过去时间的提示词： We had finished it by the time they went back 句子中的 went back 就是提示（过去时）