英语语法点.

英语语法点.
英语语法点.

英语语法点.
11.1 一般现在时的用法
1） 经常性或习惯性的动作,常与表示频腮度的时间状语连用.时间状语： every…, sometimes, at…, on Sunday.例如：
I leave home for school at 7 every morning. 每天早上我七点离开家.
2） 客观真理,客观存在,科学事实.例如：
The earth moves around the sun. 地球绕太阳转动.
Shanghai lies in the east of China. 上海位于中国东部.
3） 表示格言或警句.例如：
Pride goes before a fall. 骄者必败.
注意：此用法如果出现在宾语从句中,即使主句是过去时,从句谓语也要用一般现在时.
例：Columbus proved that the earth is round. 哥伦布证实了地球是圆的.
4） 现在时刻的状态、能力、性格、个性.例如：
I don't want so much. 我不要那么多.
Ann writes good English but does not speak well. 安英语写得不错,讲的可不行.
比较：Now I put the sugar in the cup. 把糖放入杯子.
I am doing my homework now. 我正在做功课.
第一句用一般现在时,用于操作演示或指导说明的示范性动作,表示言行的瞬间动作.第二句中的now是进行时的标志,表示正在进行的动作的客观状况,所以后句用一般现在时.
11.2 一般过去时的用法
1）在确定的过去时间里所发生的动作或存在的状态.例如：时间状语有：yesterday, last week, an hour ago, the other day, in 1982等.例如：
Where did you go just now? 刚才你上哪儿去了?
2）表示在过去一段时间内,经常性或习惯性的动作.例如：
When I was a child, I often played football in the street. 我是个孩子的时候,常在马路上踢足球.
Whenever the Browns went during their visit, they were given a warm welcome.
那时,布朗一家无论什么时候去,都受到热烈欢迎.
3）句型：It is time for sb. to do sth "到……时间了" "该……了".例如：It is time for you to go to bed. 你该睡觉了.
It is time that sb. did sth. "时间已迟了" "早该……了" ,例如It is time you went to bed. 你早该睡觉了.
would （had） rather sb. did sth. 表示'宁愿某人做某事'.例如：I'd rather you came tomorrow.还是明天来吧.
4） wish, wonder, think, hope 等用过去时,作试探性的询问、请求、建议等,而一般过去时表示的动作或状态都已成为过去,现已不复存在.例如：I thought you might have some. 我以为你想要一些.
比较：Christine was an invalid all her life.（含义：她已不在人间.）
Christine has been an invalid all her life.（含义：她现在还活着）
Mrs. Darby lived in Kentucky for seven years. （含义：达比太太已不再住在肯塔基州.）
Mrs. Darby has lived in Kentucky for seven years. （含义：现在还住在肯塔基州,有可能指刚离去）
注意： 用过去时表示现在,表示委婉语气.
1）动词want, hope, wonder, think, intend 等.例如：
Did you want anything else? 您还要些什么吗?
I wondered if you could help me. 能不能帮我一下.
2）情态动词 could, would.例如：
Could you lend me your bike? 你的自行车,能借用一些吗?
11.3 used to / be used to
used to + do："过去常常"表示过去习惯性的动作或状态,但如今已不存在.例如：
Mother used not to be so forgetful. 老妈过去没那么健忘.
Scarf used to take a walk. 斯卡夫过去常常散步.
be used to + doing： 对……已感到习惯,或"习惯于",to是介词,后需加名词或动名词.例如：
He is used to a vegetarian diet.
Scarf is used to taking a walk. 斯卡夫现在已习惯于散步了.
11.4 一般将来时
1） shall用于第一人称,常被will 所代替.will 在陈述句中用于各人称,在征求意见时常用于第二人称.例如：
Which paragraph shall I read first? 我先读哪一段呢?
Will you be at home at seven this evening? 今晚七点回家好吗?
2） be going to +不定式,表示将来.
a. 主语的意图,即将做某事.例如：What are you going to do tomorrow? 明天打算作什么呢?
b. 计划,安排要发生的事.例如：The play is going to be produced next month.这出戏下月开播.
c. 有迹象要发生的事.例如：Look at the dark clouds, there is going to be a storm. 看那乌云,快要下雨了.
3） be +不定式表将来,按计划或正式安排将发生的事.例如：
We are to discuss the report next Saturday.我们下星期六讨论这份报告.
4） be about to +不定式,意为马上做某事.例如：
He is about to leave for Beijing. 他马上要去北京.
注意：be about to do 不能与tomorrow, next week 等表示明确将来时的时间状语连用.
11.5 be going to / will 用于条件句时,be going to表将来,will表意愿.例如：
If you are going to make a journey, you'd better get ready for it as soon as possible.
Now if you will take off your clothes, we will fit the new clothes on you in front of the mirror.
11.6 be to和be going to
be to 表示客观安排或受人指示而做某事,be going to 表示主观的打算或计划.例如：
I am to play football tomorrow afternoon. 明天下午我去踢球.（客观安排）
I'm going to play football tomorrow afternoon. 明天下午我想去踢球.（主观安排）
11.7 一般现在时表将来
1）下列动词come, go, arrive, leave, start, begin, return的一般现在时可以表示将来,主要用来表示在时间上已确定或安排好的事情.例如：
The train leaves at six tomorrow morning. 火车明天上午六点开.
When does the bus star? It stars in ten minutes. 汽车什么时候开?十分钟后.
2）以here, there等开始的倒装句,表示动作正在进行.例如：
Here comes the bus. = The bus is coming. 车来了.
There goes the bell. = The bell is ringing. 铃响了.
3）在时间或条件句中.例如：
When Bill comes （不是will come）, ask him to wait for me. 比尔来后,让他等我.
I'll write to you as soon as I arrive there. 我到了那里,就写信给你.
4）在动词hope, take care that, make sure that等的宾语从句中.例如：
I hope they have a nice time next week. 我希望他们下星期玩得开心.
Make sure that the windows are closed before you leave the room. 离开房间前,务必把窗户关了.
11.8 用现在进行时表示将来
下列动词come, go, arrive, leave, start, begin, return等现在进行时可以表示将来.例如：
I'm leaving tomorrow. 明天我要走了.
Are you staying here till next week? 你会在这儿呆到下周吗?
11.9 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.
11.11 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.例如：
It is the first time that I have visited the city. 这是我第一次访问这城市.
This is the first time （that） I've heard him sing. 这是我第一次听他唱歌.
注意：It was the third time that the boy had been late.
2）This is +形容词最高级+that…结构,that 从句要用现在完成时.例如：
This is the best film that I've （ever） seen. 这是我看过的最好的电影.
（错）I have received his letter for a month.
（对）I haven't received his letter for almost a month.
11.13 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）.例如：
I have been here since 1989. 1989起,我一直在这儿.
2） since +一段时间+ ago.例如：
I have been here since five months ago. 我在这儿,已经有五个月了.
3） since +从句.例如：
Great changes have taken place since you left. 你走后,变化可大了.
Great changes have taken place since we were here. 我们走后,变化可大了.
4） It is +一段时间+ since从句.例如：
It is two years since I became a postgraduate student. 我考上研究生有两年了.
11.15 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.例如：
She said （that）she had never been to Paris. 她告诉我她曾去过巴黎.
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.例如：
When the police arrived, the thieves had run away. 警察到达时,小偷们早就跑了.
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…".例如：
We had hoped that you would come, but you didn't. 那时我们希望你能来,但是你没有来.
3） 过去完成时的时间状语before, by, until , when, after, once, as soon as.例如：
He said that he had learned some English before. 他说过他以前学过一些英语.
By the time he was twelve, Edison had began to make a living by himself. 到了十二岁那年,爱迪生开始自己谋生.
Tom was disappointed that most of the guests had left when he arrived at the party.
汤姆失望了,因为他到达晚会时,大部分客人已经走了.
11.17 将来完成时
1） 构成will have done
2） 概念
a. 状态完成：表示某事继续到将来某一时为止一直有的状态.例如：
They will have been married for 20 years by then. 到那时他们结婚将有二十年了.
b. 动作完成：表示将来某一时或另一个将来的动作之前,已经完成的动作或获得的经验.例如：
You will have reached Shanghai by this time tomorrow. 明天此时,你已经到达上海了.