英语语法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。那么,英语现在完成时的句子结构和语法特点是怎样的呢?下面为您讲解一下。
一、过去完成时的结构特点
概念: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( past-in-the-past)”。
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过去完成时 过去时 现在进行时
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。
They had already had breakfast before they arrived at the hotel. She had finished writing the composition by 10 :00 this morning.
二、过去完成时的判断依据
1. 由时间状语来判定
一般说来,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:
( 1 ) by + 过去的时间点。如:
I had finished reading the novel by nine o'clock last night.
( 2 ) by the end of + 过去的时间点。如:
We had learned over two thousand English words by the end of last term.
( 3 ) before + 过去的时间点。如:
They had planted six hundred trees before last Wednesday.
2. 由“过去的过去”来判定。 过去完成时表示“过去的过去”,是指过去某一动作之前已经发生或完成的动作,即动作有先后关系,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:
( 1 )宾语从句中,当宾语从句的主句为一般过去时,且从句的动作先于主句的动作时,从句要用过去完成时。在told, said, knew, heard, thought等动词后的宾语从句。
如: She said that she had seen the film before.
( 2 )状语从句中,在时间、条件、原因、方式等状语从句中,主、从句的动作发生有先后关系,动作在前的,要用过去完成时,动作在后的要用一般过去时。
如: When I got to the station, the train had already left. After he had finished his homework, he went to bed.
注意: before, after ,as soon as引导的时间状语从句中,由于 before 和 after 本身已表达了动作的先后关系,若主、从句表示的动作紧密相连,则主、从句都用一般过去时。如:
Where did you study before you came here?
After he closed the door, he left the classroom.
(3)表示意向的动词,如hope, wish, expect, think, intend, mean, suppose等,用过去完成时表示"原本…,未能…"
We had hoped that you would come, but you didn't. 3. 根据上、下文来判定。
I met Wang Tao in the street yesterday. We hadn't seen each other since he went to Beijing.
三、过去完成时的主要用法
1. 过去完成时表示一个动作或状态在过去某一时间或动作之前已经完成或结束,即发生在“过去的过去”。如:
When I woke up, it had stopped raining. 我醒来时,雨已经停了。(主句的动作发生在“过去的过去”)
2. 过去完成时是一个相对的时态,表示的是“过去的过去”,只有和过去某一时间或某一动作相比较时才使用它。如:
He told me that he had written a new book. (had written 发生在 told 之前 )
3. 过去完成时需要与一个表示过去的时间状语连用,它不能离开过去时间而独立存在。