(用过去完成式表示与过去相反的事实)那老人看着照片，他觉得仿佛回到20年前的时光。
The old man looked at the picture, he felt as though he had gone back to time 20 years ago.
当我们使用现在完成式时，是和现在有关联的。
When we use the present perfect, there is a connection with now.
以上是一些完成式之间的微妙差异。
These are just some of the shades of difference between the perfect tenses.
现在完成式强调过去所发生的事情对现在的影响。
The present perfect tense emphasizes the effect of the past action on the present.
延续性动词和非延续性动词是英语教学中的一个难点，特别是完成式教学中的一个重点。
It is difficult to deal with durative and non-durative verbs in English teaching, especially when used in perfect tenses.
其表现形式体现在从句的谓语动词需要用一般过去式或者过去完成式。
I'd rather stay than go out. I would rather you had not done anything about it at that time.
你应该记住过去未完成式是指过去进行的或重复的动作，你在过去正在做的事或习惯的事。
One thing you need to remember about the imperfect past tense—it is for activities that were ongoing or repeated; something you were doing in the past, or something you used to do.
你应该记住过去未完成式是指过去进行的或重复的动作，你在过去正在做的事或习惯的事。
One thing you need to remember about the imperfect past tense—it is for activities that were ongoing or repeated; something you were doing in the past, or something you used to do.
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