1一般现在时的用法
1）表示经常性或习惯性的动作，常与表示频度的时间状语连用。
例： every…, sometimes,ofen,always,usually, twice a week, at…, on Sunday等。
I leave home for school at 7 every morning.
He watches Tv once a week .
2）表示普遍真理，客观存在，科学事实。
The earth moves around the sun.
Shanghai lies in the east ofChina.
3）格言或警句。
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..
4）表示现在时刻的状态、能力、个性或爱好。
I don't want so much.
Ann Wang writes good English but does not speak well.
比较：Now I put the sugar in the cup.
I am doing my homework now.
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。再如：Now watch me, I switch on the current and stand back.
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。
1）在确定的过去时间里所发生的动作或存在的状态。
时间状语有：yesterday, an hour ago, the other day, in 1982，yesterday morning (afternoon, evening…)，last night (week, month, year…), a moment ago , a week ago, three years ago… just now,等。
Where did you go just now?
2）表示在过去一段时间内，经常性或习惯性的动作。
When I was a child, I often played football in the street.
Whenever the Browns went during their visit, they were given a warm welcome.
3）句型：
It is time for sb. to do sth "到……时间了" "该……了"
It is time sb. did sth. "时间已迟了" "早该……了"
It is time for you to go to bed. 你该睡觉了。
It is time you went to bed. 你早该睡觉了。
4）wish, wonder, think, hope 等用过去时，作试探性的询问、请求、建议等。
I thought you might have some. 我以为你想要一些。
注意：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。
Christine was an invalid all her life.
(含义：她已不在人间。)
Mrs. Darby lived in Kentucky for seven years.
(含义：达比太太已不再住在肯塔基州。)
1）表示现在( 指说话人说话时) 正在发生的事情。
We are waiting for you.
2）表示长期的或重复性的动作，说话时动作未必正在进行。
Mr. Green is writing another novel. (说话时并未在写，只处于写作的状态。)
She is learning piano under Mr. Smith.
3）瞬时动词的进行时一定表示将来的含义。
瞬时动词：come,go,arrive,leave,finish,end,start,begin等。
We are arriving at London.
持续动词的进行时需要加表示将来的时间状语或有将来的语境时才能表将来。
I am travelling next month.
4）与always, constantly, forever 等词连用，表示反复发生的动作或持续存在的状态，往往带有说话人的主观色彩。
You are always changing your mind.
1）过去进行时主要表示过去某个时刻正在进行的动作，常和表示过去的状语连用。
例如：（just）then 那时，当时；at this/that time 在这/那时 yesterday afternoon昨天下午；at nine 在九点；last night 昨晚；（at）this time yesterday在昨天这个时候
但在不少情况下，没有表示时间的状语，这时需要通过上下文来表示。
What were you doing at nine last night? 昨晚九点的时候，你在做什么？
I was watching TV at home yesterday afternoon. 我昨天下午正在家里看电视。
They were playing football at this time yesterday.昨天这个时候他们在踢足球。
2）过去进行时也可以表示过去某一段时间内正在进行的动作。
常与those days, the whole morning, from 8:00 to 12:00 last night等时间状语连用。
From 1983 to 1998 , he was teaching at Yale . 从1983到1998年，他正在耶鲁大学教书。
They were building a bridge last winter . 去年冬天他们正在造一座桥。
3）过去进行时表示过去将要发生的动作。
现在进行时可以表示将来的动作，同样，过去进行时也可以表示从过去某时看来将要发生的动作，常用在间接引语中。
Lucy arrived in Beijing last Friday. But she was leaving for Hong Kong the next morning.上周五Lucy到达北京，但第二天早晨就要动身去香港了。
She asked him if he was coming back for lunch. 她问他午饭是否准备回来吃。
4）过去进行时与频度副词always forever， continually， constantly等连用时表示过去经常反复的动作，常常带有埋怨、讨厌、赞扬或喜爱等情绪。
My sister was always forgetting things.(表示埋怨)
He was always helping others. (表示赞扬)
1）表示将来某个时间要发生的动作或存在的状态，也表示将来经常或重复发生的动作。
时间状语：tomorrow , soon , next Monday , next year , next weekend , this afternoon , this evening ……
2）will do 表示主观意愿做某事。
I will see a movie this morning.
表示客观的不以人的意志为转移的客观将来。
Fish will die without water.
表示临时决定。
——Mom, where is the newspaper?
——Wait a moment. I will get it for you.
3）be going to +do 表示计划，安排要发生的事。
The play is going to be produced next month。
表示有迹象要发生的事
Look at the dark clouds.There is going to be a storm.
立足于过去某一时刻，从过去看将来，常用于宾语从句中。
时间状语：the next day(morning, year…),the following month(week…),etc.
He said he would go to Beijing the
I didn't know if she was going to come。
Wang Lei said that she was going to visit her uncle next Saterday。
1）表示过去发生或已经完成的某一动作对现在造成的影响或结果。
标志词：already, yet, just, ever, never, before
I have finished my homework. 我做完家庭作业了。(过去某时开始做，到现在已完成。)
