英语新概念第二册14课Lesson 14 Do you speak English?I had an amusing e

英语新概念第二册14课
Lesson 14 Do you speak English?
I had an amusing experience last year.一（ After I had left a small village in the south of France,I drove on to the next town.） On the way,a young man waved to me.二（I stopped and he asked me for a lift.） As soon as he had got into the car,I said good morning to him in French and he replied in the same language.三（Apart from a few words,I do not know any French at all.）Neither of us spoke during the journey.四（I had nearly reached the town,when the young man suddenly said,very slowly,"Do you speak English?'） As I soon learnt,he was English himself!'
这篇课文教的是过去完成式,有时间对比的话,句一,先前发生的事应该用过去完成式,但句二（我停下,他让我搭我的车）也有时间对比,为什么不用过去完成式?而句三,更不明白为什么用一般现在式.句四也是过去完成式.这篇课文里的过去式和过去完成式在这是否可以互换?什么时侯用过去,什么时侯用过完,有点搞混了.