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现在完成时
现在完成时用来表示之前已发生或完成的动作或状态，其结果的确和现在有联系。动作或状态发生在过去但它的影响现在还存在；也可表示持续到现在的动作或状态。其构成： have (has) +过去分词。
比较过去时与现在完成时
1）过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。
2）过去时常与具体的时间状语连用，而现在完成时通常与模糊的时间状语连用，或无时间状语。
一般过去时的时间状语:
yesterday, last week，…ago, in1980, in October, just now, 具体的时间状语
共同的时间状语:
this morning, tonight,this April, now, once，before, already, recently，lately
现在完成时的时间状语
for, since, so far, ever, never, just, yet,till / until, up to now, in past years, always,不确定的时间状语
3）现在完成时可表示持续到现在的动作或状态，动词一般是延续性的，如live, teach, learn, work, study, know.
过去时常用的非持续性动词有come, go, leave, start, die, finish, become, get married等。
举例：
I saw this film yesterday.
（强调看的动作发生过了。）
I have seen this film.
（强调对现在的影响，电影的内容已经知道了。）
He has been in the League for three years.
(在团内的状态可延续)
He has been a League member for three years.
(是团员的状态可持续)
He joined the League three years ago.
( 三年前入团，joined为短暂行为。)
句子中如有过去时的时间副词（如 yesterday, last, week, in 1960）时，不能使用现在完成时，要用过去时。
（错）Tom has written a letter to his parents last night.
（对）Tom wrote a letter to his parents last night.
用于现在完成时的句型
1）It is the first / second time…. that…结构中的从句部分，用现在完成时。
It is the first time that I have visited the city.
It was the third time that the boy had been late.
2）This is the… that…结构，that 从句要用现在完成时.
This is the best film that I"ve (ever) seen.
这是我看过的最好的电影。
This is the first time (that) I"ve heard him sing.这是我第一次听他唱歌。
注意：非延续性动词的否定形式可以与表示延续时间的状语连用。即动作不发生的状态是可以持续的。
（错）I have received his letter for a month.
（对）I haven"t received his letter for almost a month.
比较since和for
Since 用来说明动作起始时间，for用来说明动作延续时间长度。
I have lived here for more than twenty years.
I have lived here since I was born..
注意：并非有for 作为时间状语的句子都用现在完成时。
I worked here for more than twenty years.
(我现在已不在这里工作。)
I have worked here for many years.
(现在我仍在这里工作。)
小窍门：当现在完成时+一段时间，这一结构中，我们用下面的公式转化，很容易就能排除非延续动词在完成时中的误使。
1)(对) Tom has studied Russian for three years.
= Tom began to study Russian three years ago, and is still studying it now.
2)(错) Harry has got married for six years.
= Harry began to get married six years ago, and is still getting married now.
显然，第二句不对，它应改为 Harry got married six years ago.或 Harry has been married for six years.
since的四种用法
1) since +过去一个时间点(如具体的年、月、日期、钟点、1980, last month, half past six)。
I have been here since 1989.
2) since +一段时间+ ago
I have been here since five months ago.
3) since +从句
Great changes have taken place since you left.
Considerable time has elapsed since we have been here.
4) It is +一段时间+ since从句
It is two years since I became a postgraduate student.
延续动词与瞬间动词
1) 用于完成时的区别
延续动词表示经验、经历； 瞬间动词表示行为的结 果，不能与表示段的时间状语连用。
He has completed the work.他已完成了那项工作。 (表结果)
I"ve known him since then. 我从那时起就认识他了。(表经历)
2)用于till / until从句的差异
延续动词用于肯定句，表示"做……直到……" 瞬间动词用于否定句，表示"到……，才……"
He didn"t come back until ten o"clock.
他到10 点才回来。
He slept until ten o"clock.
他一直睡到10点。
现在完成进行时
一、现在完成进行时的构成方法
现在完成进行时由“have/has + been +现在分词”构成。
二、现在完成进行时用法
1．现在完成进行的基本用法表示现在以前这一段时间里一直在进行的动作，这动作可能仍在进行，也可能已停止。
例如：
It has been raining since last Monday. 自上周一以来就一直在下雨。
She"s been watching television all day. 她看了整整一天电视。
2．现在完成进行时有时表示根据直接或间接的证据得出的结论。
例如：
I am very tired. I"ve been typing letters all day. 一整天都在打信件，我太累了。
Susan eyes are red. She has been crying. 苏姗一直在哭，眼睛都哭红了。
现在完成时与现在完成进行时的区别
1. 现在完成时通常只陈述事实，而现在完成进行时还可表示一种感情色彩。
例如：
I have waited for two hours. 我等了两小时。（陈述事实）
I have been waiting for two hours. 我等了两个小时。（等得好辛苦）
2. 现在完成进行时通常用来谈论较短暂的动作或情况，若要谈论时间延续较长的动作或情况或永久性情况，则通常用现在完成时。
例如：
He has lived in Paris. 他(一直)住在巴黎。
He has been living in Paris. 他(目前)住在巴黎。
3. 不用于进行时态的动词通常也不用于现在完成进行时，但它们可以用于现在完成时。
例如：
They"ve been married for twenty years. 他们结婚已二十年了。
The war has lasted for a long time. 这场战争持续了很长时间。
4. 现在完成进行时不用于被动语态，若要用可用现在完成时的被动语态代替。
例如：
The house has been painted for a month. 这房子已经粉刷了一个月。
The problem has been studied
过去完成时
1） 概念：表示过去的过去
----|-----------|-----------|---->其构成是had +过去分词构成。
那时以前那时现在
2） 用法
a.在told, said, knew, heard, thought等动词后的宾语从句。
She said (that) she had never been to Paris.
b. 状语从句
在过去不同时间发生的两个动作中，发生在先，用过去完成时；发生在后，用一般过去时。
When the police arrived, the thieves had run away.
c. 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)过去完成时的时间状语before, by, until , when, after, once, as soon as。
He said that he had learned some English before.
By the time he was twelve, Edison had began to make a living by himself.
Tom was disappointed that most of the guests had left when he arrived at the party.
注意：had no … when还没等…… 就……
had no sooner… than刚…… 就……
He had no sooner bought the car than he sold it.
将来进行时
1) 概念：表示将来某时进行的状态或动作，或按预测将来会发生的事情。
She"ll be coming soon.
I"ll be meeting him sometime in the future.
注意：将来进行时不用于表示"意志"，不能说 I"ll be having a talk with her.
2）常用的时间状语
Soon, tomorrow, this evening，on Sunday, by this time，tomorrow, in two days, tomorrow evening
By this time tomorrow, I"ll be lying on the beach.
过去将来时
1. 过去将来时的定义
过去将来时主要用于表示过去某个时候看来即将发生的动作或存在的状态。如：
He said he would come here the next Friday. 他说他下周星期五来这儿。
I knew that he would help us when we were in trouble. 我知道当我们陷入困境时它会帮助我们。
2. 过去将来时的时间状语：
1) at six the next morning, at two the next afternoon, at eight the next night, the next day,the next Friday, the next week, the next month, the next year
2)the following day, the following week，the following month,the following year
3)two days later, three weeks later, four years later
4) after10 o"clock, after 10 o"clock in the morning, after 9 o"clock
5)when,after引导的时间状语从句。
3. 过去将来时的结构
（一）由助动词“would/should+动词原形”构成,should主要用于主语是第一人称时;would可用于各种人称。
He said he would come to see me.
他说他要来看我。
Whenever we had trouble, he would come to help us.
不论何时我们遇到困难,他总会给予帮助。
（二）“was/were+goingto+动词原形”。常可用来表示按计划或安排即将发生的事。例如：
No one knew when he was going to come.
没有人知道他什么时候来。
He said that I was going to be sent to meet her at the railway station. 他说将要拍我去火车站接她
此结构还可表示根据当时情况判断有可能但不一定会发生某事。例如：
It seemed as if it was going to rain.
看来好像要下雨。
（三）come，go，leave，arrive，start等动词可用过去进行时代替过去将来时。例如：
He said the train was leaving at six the next morning.
他说火车将于第二天早晨六点离开。
She told me she was coming to see me.
（四）条件状语从句和时间状语从句中须用一般过去时代替过去将来时。例如：
I didn"t know when she would come，but when she came I would let you know.
我不知道她什么时候来，但她来了我会告诉你。
(五) was / were to + 动词原形。如：
The building was to be completed the next month. 这座建筑改在下个月竣工。
Li Lei was to arrive soon. 李蕾很快就要到了。
（六） was / were about to + 动词原形。如：
We were about to leave there when it began to rain heavily and suddenly. 就在我们要离开时，天突然下起了大雨。
He was about to have lunch when the bell rang. 就在他要吃中饭的时候，门铃响起来了。
3. 过去将来时的用法
(1) 过去将来时，一般用于主句为过去时的宾语从句中。如：
He said he would stay with us. 他说他要与我们呆在一起。
He said he would never go there again. 他说他绝不会再去那儿。
(2) 过去将来时，用于虚拟语气中。如：
If I were you, I would not do that. 要是我是你的话，我就不会那样做。
If he were here, he would show us how to do it. 如果他在这儿，他就会向我们展示该如何做了。
（3）was / were going to + 动词原形；was / were to + 动词原形；was / were about to + 动词原形等结构都可表达当 一 种未曾实现的意图或打算。如：
The conference was going to be held the next month. 会议下个月开。
We were to have our class at eight. 八点我们该上课了。
I was about to tell him about it when Wu Dong got in. 就在我要告诉他时，吴东进来了。