1. 这位足球明星脱离了以前的俱乐部并计划加入另一个俱乐部。

2. 当他向我解释后，我开始意识到我错了。

【翻译】

1. The football star left the old club and planned to join another. 

本句：left 和planned 是两个并列的过去发生的动作，先后关系明确，尽管left 早于planned，但逻辑关系已经表明时间的先后，所以，left无须使用过去完成时。类似的例句：

He came in, sat down and drank a cup of tea.

本句有3个动词，先后关系明确。都用一般过去时即可。

2. After  he explained to me, I began to realize that I was wrong.

本句是个主从句，虽然从句explained 早于bengan，但是引导从句的时间连词after 已经表明两个动作的先后，所以，explained 也无需使用完成时。

【注意】当一个主从句中的两个动作无法从上下文判断先后时，则必须借助时态。注意以下例句的过去完成时：

结合下面的20个例句，请仔细体会“过去完成时”的用法，为什么使用“过去完成时”？如果改为一般过去时的话，句子表达是否清晰？

1. Tom was disappointed that most of the guests had left when he arrived at the party.

2. The children ran away because they had broken the window.

2. By the time he was twenty, he had written five novels.

3. How many English songs had you learnt by the end of last term?

4. As soon as the sun had set, we returned to our hotel.

5. How long had Brown lived in the south before he came here?

6. When he had eaten his lunch he asked for a glass of water.

7. I hadn’t understood the problem until the teacher explained it.

8. They had just got home when it began to rain.

9. I had been at the bus stop for 20 minutes when a bus finally came.

10. He said he had worked in that factory since 1949.

11. Mr. Smith died yesterday. He had been a good friend of mine

12. I didn’t know a thing about the verbs, for I had not studied my lesson.

13. I returned the book that I had borrowed.

14. I met Tom yesterday. We hadn't seen each other since he went to Beijing.

15. I thought I had sent the letter a week before.

16. When I woke up, it had already stopped raining.

17. We had hoped to be able to come and see you, but you were not at home.

18. It was the third time that he had been out of work that year.

19. We had learned over two thousand English words by the end of last term.

20. They had planted six hundred trees by last Wednesday.