过去完成时讲解及练习题(精讲)概念：过去完成时用来描述过去发生或已经完成的动作对现在造成的影响或结果，或从过去已经开始，持续到现在的动作或状态。
时间状语：一些常用的时间状语包括recently。
lately。
since…for…,in the past few years等等。
基本结构：过去完成时的基本结构是“have/has + 过去分词”。
否定形式：要表达否定，需要在“have/has”后面加上“not”，即“have/has + not + 过去分词”。
一般疑问句：如果要表达一般疑问句，需要将“have/has”提前。
过去完成时表示在过去某一时间或动作之前已经发生或完成了的动作，即“过去的过去”。
构成：过去完成时由“助动词had + 过去分词”构成，其中had通用于各种人称。
例如：They had already had XXX（他们在到达酒店之前已经吃过早餐了。
）XXX 10:00 this morning.（今天早上10点前，她已经写完了作文。
）过去完成时的判断依据有两个：1.由时间状语来判定。
各种时态都有特定的时间状语。
与过去完成时连用的时间状语有：by + 过去的时间点，by the end of + 过去的时间点，before + 过去的时间点等等。
例如：I had finished reading the novel by nine o'clock last night.（昨晚9点前，我已经读完了这本小说。
）XXX English words by the end of last term.（上学期结束时，我们已经学了2000多个英语单词。
）They had XXX last XXX.（上XXX之前，他们已经种了600棵树。
）2.由“过去的过去”来判定。
过去完成时表示“过去的过去”，即过去某一动作之前已经发生或完成的动作，动作有先后关系，动作在前的用过去完成时，在后的用一般过去时。
这种用法常出现在宾语从句中。
When the main clause of a subordinate clause is in the simple past tense and the n of the subordinate clause occurred before the n of the main clause。
the subordinate clause should use the past perfect tense。
This rule XXX "told," "said," "knew," "heard," and "thought." For example。
"She said that she had seen the film before."XXX such as time。
n。
reason。
and manner clauses。
where there is a sequence of events。
the past perfect tense is used for the n that occurred first。
and the simple past tense is used for the nthat occurred later。
For example。
"When I got to the n。
the train had already left," and "After he had finished his homework。
he went to bed." However。
if the main and XXX closely connected。
and the XXX "before" and "after," both clauses can use the simple past tense。
For example。
"Where did you study before you came here?" and "After he closed the door。
he left the classroom."XXX XXX。
such as "hope," "wish," "expect," "think," "intend," "mean," and "suppose," use the past perfect tense to express something that was intended but did not happen。
For example。
"We had hoped that you would come。
but you didn't."XXX that an n or state was XXX time or n in the past。
indicating the "past in the past." For example。
"When I woke up。
it had ped raining." It is a relative tense。
and is only used when compared to a certain time or n in the past。
For example。
"Hetold me that he had written a new book" (the n of "had written" occurred before the n of "told").过去完成时需要与一个表示过去的时间状语连用，不能独立存在。
通常与时间副词和引导短语或从句连用，例如：Before she came to China。
Grace had taught English in a middle school for about five years。
Peter had collected more than 300 Chinese stamps by the time he was ten。
这个时态表达的是过去某一时间之前已经开始并且尚未结束的动作或状态。
现在完成时则表示过去发生的动作对现在产生的影响或结果，它的结构为"助动词have (has) +过去分词"。
而过去完成时则更强调"过去的过去"，只有和过去某时或某动作相比较时才使用。
例如：I have learned 1000 English words so far。
到目前为止我已经学会了1000个英语单词。
I had learned 1000 English words till then。
到那时为止我已经学会了1000个英语单词。
在对话中，如果说"I'm sorry to keep you waiting." 对不起，让你久等了。
那么回答"Oh。
not at all。
I have been here only a few minutes." 没什么，我只等了几分钟。
这里的现在完成时，表示等待的动作从过去某一时间点开始一直持续到现在。
而过去完成时则常常用于询问过去某个时间点之前的事情，例如："John returned home yesterday。
Where had he been?" XXX昨天回到家的。
他去哪儿了？这里的过去完成时表示XXX在回家之前去了哪些地方，即"过去的过去"。
总之，过去完成时与一般过去时的区别在于前者强调"过去的过去"，而后者则只表示过去发生的动作或状态。
同时，过去完成时需要与时间状语连用，不能独立存在。
C。
where did I goD。
where I have been答案：A改写：During the summer holidays。
he asked me where I had been or where I had gone.2.The guests _____ when the hostess came back with more food.A。
have XXX。
had XXXC。
XXX答案：B改写：When the hostess came back with more food。
the guests had already XXX.3.I _____ to call you。
but I ot.A。
XXXXXX答案：A改写：I had meant to call you。
but I ot.4.They _____ for the bus for half an hour before it finally arrived.A。
had XXXC。
XXX答案：A改写：They had been waiting for the bus for half an hour before it finally arrived.5.After she _____ her homework。
she went to bed.A。
finishedB。
had finishedC。
finishesD。
finish答案：B改写：After she had finished her homework。
she went to bed.2.What did Jane do by the time he was seven?A。
did。
doB。
has。
doneC。
did。
didD。
had。
done3.I had learned 900 English words by the time I was ten.A。
XXX4.She had lived here for several years.A。
had。
a fewB。
has。
severalC。
had。
a lot ofD。
has。
a great deal ofXXX。
I had already cooked dinner.A。
XXX cooked6.She said she had already seen the principal.A。