语法精讲
一、过去完成时的构成
过去完成时的构成：had done
过去完成时的被动式：had been done
?She had learned Chinese before she came to China.她来中国前已经学过中文了。
?I found the lecture hard to follow because it had started when I arrived.我发现这场讲座很难听懂，因为我到的时候讲座已经开始了。
?In the 1950s in the USA, most families had just one phone at home, and wireless phones hadn't been invented yet. 20世纪50年代，在美国大多数家庭里只有一部电话，那时无绳电话还没有被发明。
?How many buildings had been destroyed when the earthquake ended？地震结束时有多少建筑物被摧毁了？
二、过去完成时的用法
1．表示在过去某一时间或动作之前已经完成或结束的动作。
?The student completed this experiment to make come true what Professor Joseph had said.为了使约瑟夫教授所说的成为现实，这个学生完成了这个实验。
?A few months after he had arrived in China, Mr. Smith fell in love with the people and culture there.史密斯先生在来到中国几个月之后，就爱上了那里的人和文化。
?By nine o'clock last night, we had finished most of the work.到昨晚9点钟，我们已经完成了大部分的工作。
?She had learnt about 500 English words before she went to junior middle school.在上初中之前，她已经学了大约500个英语单词。
[即学即练1] 单句语法填空
①One morning she told her children about a family she ________ (visit) the day before.
②By about 6000 BC, people ________ (discover) the best crops to grow and animals to raise.
③We found that the least wellliked teens ________ (become) more aggressive over time toward their classmates.
④I was sent to the village last month to see how the development plan ________ (carry) out in the past two years.
