在英语句子中，不同时间所发生的动作或存在的状态，要使用不同的动词形式，这一点和汉语不同，这种谓语动词的变化形式，称之为时态。谓语动词共有十六种时态，常用的有八种，总结如下包括：一般现在时，一般过去时，一般将来时，现在进行时，过去进行时，现在完成时，过去完成时，过去将来时。另外还有现在完成进行时，过去完成进行时等。
(一)一般现在时
1. 表示经常性、习惯性的动作或现阶段内(包括过去、现在、将来在内的一段时间内)所存在的状态、特征和客观真理。例如对比：
1)I am student. 2)I saw him just now.
①我是个学生。其含义包括昨天、前天、今天、明天等在内的现阶段的状况，用了一般现在时。②我刚才看见他了。指过去发生过的动作，现在已结束，就用过去时。一般现在时常与下列时间状语连用。如：often, always, usually, sometimes, every day等，掌握时间状语，有利于判断时态。助动词第三人称单数用does，其余人称用do，如：
He gets up at 6∶00 every day. (经常性)
I am glad to meet you. (现在的状态)
My mother is a teacher. (现阶段的状况)
Light travels faster than sound. (真理)
He doesn't to washing. (否定句)
Do you speak English?(疑问句)
He is always the first to get to school.
Usually he gets to his office at seven.
注意：always还可以和进行时连用，表示说话人的表扬和批评等感情色彩。如：
He is always asking the same question.
He is always helping the old man.
2. 在时间、条件、让步、方式状语从句中，用现在时态，其中包括一般现在时，代表将来，不用助动词will或shall. 如：
I'll tell him as soon as he comes.
It won't be long before we meet again.
Even if you offer him much more money, he won't accept it.
We'll stay a little longer even though it is late.
If you work hard at it, you will make progress.
You will be late unless you hurry.
I'll do as my teacher says.
You should state(陈述)the facts as they are.
有时条件句中出现will，will是情态动词，表示愿意，例如：If you will wait a few minutes, I'll tell the manager. 如果你肯(愿意)等候几分钟，那我就去通知经理。(直译)
实际上这是一句客套话，相当于：
Please wait a few minutes, I'll tell the manager.
所以上面的句子可以意译为“请等一下，我就去通知经理。”又如：
If you will take off your clothes, we'll fit the new clothes on you. 相当于Please take off your clothes, we'll fit the new clothes on you.
If you will be quiet, I'll tell you what has happened.
还要注意when, if等连词引导的其他从句，该用什么时态就用什么时态。如：
I don't know when he will come. (宾语从句)
我不知道他什么时候回来。
I don't know if he will come. (宾语从句)
我不知道他是否能来。
When he will arrive is unknown. (主语从句)
他什么时候能来还不知道。
We are fixing the time when the meeting will be held. 我们正在确定开会的时间。
书报的标题、戏剧的场景介绍常用一般时或现在进行时，如高中课本The Necklace一课Scene1 A park in Paris, 1870. Jeanne (J) is sitting in the park. Mathilde(M) walks towards her.
4. 一般现在时可用来代表将来时，表示按计划、按时间表进行的动作，句中常带有时间状语，如：
A: When does the train for Beijing start?
B: It starts at six in the morning.
The first class begins at eight. I am afraid I will be late for it.
上面两例句都是将来时的语境，但都分别用了现在时starts, begins. 能够这样使用的大多是些瞬间动词，如：begin, come, open, close, leave, go, arrive, start, stop, return等。
(二)一般过去时
1. 表示过去某时间发生的动作、存在的状态，或过去一段时间内习惯性、经常性动作，时间状语除了像in 1978, last year, yesterday, just now, a few days ago等外，也可用often, always, usually等，还可用used to和would+ 动词原形，或通过时间状语从句来表达，如：when I was a child…. 助动词用did.
He was born in 1978.
I graduated from school last year.
When I was a child, I learned to play the piano.
I often got up early and took exercise in those days.
I remember when this used to be a quiet village.
I would get up early when I worked on my father's farm.
He didn't go to bed until he finished picking up BBC English.
During the vacation I would swim in the sea.
2. 在时间、条件、让步、方式状语从句中，如果主句是过去将来时，从句用过去时态，其中包括一般过去时代表过去将来，即从句中不用would或should。如：
He said that if we gave him more time, he would do it better.
I knew I could not finish the homework before he came.
We would finish it on time even if we had difficulties.
He told us that he would join us as soon as he came back.
I promised that I would do as my teacher said.
3. 表示一系列发生的动作，尽管动作有先后，都用过去时，而不分哪个动作是过去时，哪个动作是过去完成时，并且在最后两个动词之间用and连结，如：
He put on his best clothes, took a small bag, went to the station and got into the station.
She went to the market, bought some eggs and came back home at noon.
4. 注意下列情况过去时态的使用。如：
Sorry, I didn't know you were here.
“很抱歉，不知道您在这儿。”按英语的实际意思是，刚才不知道您在这儿，现在看到您，现在是知道了，所以用过去时表示先前不知道您那会儿就在这儿。类似的例子还有：
--You have been allowed to go out. Why are you still standing here?
--Sorry, I didn't realize you wanted me to go at once.
(三)一般将来时
一般将来时表示未来的动作或存在的状态，其表达形式有几种：
1. 用shall或will+ 动词原形。shall仅用于第一人称，即I, we作主语时，will用于所有人称(包括第一人称)。如：
If time permits, we shall/will visit the Palace.
Jenny will have a sleep-over Saturday.
There will be a rock concert at the weekend.
注意：在时间、条件、让步、方式状语从句中不用will, shall表示将来，这一点请参阅一般现在时。
2. be going to+ 动词原形，表示即将发生的事情或近期准备、打算做某事。如：
Be careful! The bicycle is going to fall down. (即将发生)
Dark black clouds are in the sky. There was going to be a thunderstorm.
I am going to send him a card on his birthday. (打算)
They are going to have a football match this afternoon.
He isn't going to see a film after school.
Are you going to go fishing this Sunday?
She is going to be a teacher in a few months.
A new film is going to be shown in this cinema tonight.
am do
is going to be done
are be
be going to结构和will, shall均可表示将来，有时意义无大区别可以互换，有时不能，如：
I will have my hair cut this afternoon. 也可以说
I am going to have my hair cut this afternoon.
Look! The sky has clouded over. It is going to rain.
即将下雨，不宜用will.
3)I hope that it won't rain tomorrow.
不是马上下雨，又不可能是计划下雨，不宜用be going to.
4)--Sorry, I forgot to post your letter.
--Never mind. I'll post it myself.
原来计划让别人邮，没邮成，现在自己来邮，不宜用be going to.
3. 某些瞬间动词可用现在时和进行时表示按计划即将发生的动作。如动词：come, go, leave, arrive, start, stay, move等，如：
He is leaving for HongKong tomorrow.
=He will leave for Hongkong tomorrow.
Bob is coming with me to the airport.
How long are you staying in Xi'an?
其中按时间表进行的动作多用一般时态表达，句中常有时间状语，而即将发生的动作多用进行时态，例如：
Go aboard, please. The ship .
A. is leaving B. leaves C. shall leave D. leave
答案是A。不是B，强调即将发生。
The ship leaves at 10∶00 a. m.
谓语动词是leaves, 而不是is leaving，强调每日上午十点这只船出发。
4. be (just) about to+ 动词原形，表示即将发生的事，常译“刚要……，就要……”。如：
There goes the bell. The film is about to begin.
Look. The players are going to the field. The game is about to begin.
5. be to+ 动词原形，表示：
(1)按计划或安排要做的事，(接近be going to, 可译为“将要”、“打算”、“定于……”)
An English examination is to take place next Monday.
A New Year's party is to be held next Saturday.
We are to meet at the school gate at six o'clock.
I am to play Mick at tennis.
(2)用不定式的完成式表示“本打算……”
We were to have held the sports meet, but the rain stopped it.
I was to have seen the film yesterday, but I was held up in my office.
(3)be to do/be接近情态动词should, must, have to, ought to的用法，表示“应该”的意思。
What should I do then?
鯳hat am I to do then?
You mustn't smoke in this room.
鯵ou are not to smoke in this room.
He ought to hand in his exercise book.
鯤e is to hand in his exercise book.
All these things ought to be answered for.
鯝ll these things are to be answered for.
(4)可能发生的事(接近can, may)
I am not sure whether he is to come tonight.
鯥 am not sure whether he can come tonight.
My keys are nowhere to be found.
鯩y keys may be found nowhere.
If we are to be there in time, we'll have to hurry up.
6. 其他形式代表未来动作的
want to do/be
I want to be a teacher in the future.
mean to do
What do you mean to do with your old bike?
intend to do
I intend to come back soon.
be likely to do
An accident is likely to happen in the rush hour.
would like to do
I'd like to go skating with you.
(四)过去将来时
从过去某一时刻看将来要发生的动作或存在的状态，通常用于主句谓语动词为过去时的宾语从句中(或者说间接引语中)，其构成，把一般将来时中的助动词will，改为would, shall改成should+ 动词原形。一般将来时所用的各种方法，在过去将来时里，照样使用，只不过动词或助动词都用过去时，对比如下：
一般将来时 过去将来时
will, shall would, should
am/is was
going to going to
are were
am/is was
about to about to
are were
am/is was
to to
are were
want to wanted to
Jenny said she would have a sleep-over Saturday the next week.
I never thought you were going to send me a card.
He said he was leaving for Hongkong the following day.
I was told that the train started at 10∶00.
We were about to leave when it began to rain.
The manager said they were to have a meeting the next Monday.
I was to have seen the film yesterday, but I was too busy.
They were to have helped us, but they didn't come.
最后两例都表示原本打算做某事，实际未做成，“打算”发生在过去的过去，用was/were to have done来表达。
He got up early and wanted to meet his friend at the station.
If you would lend me ￡ 5 until Monday, I should be grateful.
后例中would出现在条件句，是情态动词表示愿意、愿望，用这种方式提出请求，否则在时间、条件、让步、方式状语从句中，不用would或should(在主句的谓语动词是过去将来时的情况下)，而用过去时态表达。
(五)现在进行时
现在进行时由am/is/are+ doing构成。
1. 表示说话时正在进行的动作。如：
What are you doing now?
Look, they are playing chess.
2. 表示现阶段内在进行的动作，但不一定在说话时进行。
The population of the world is increasing.
Man is doing something to prevent pollution.
3. 在时间、条件等状语从句中，用现在进行时代替将来进行时。
If I am sleeping when he comes, wake me up, please.
Make notes next time you are listening to the teacher.
4. 表示感觉、愿望和状态的某些动词，一般不用进行时，如：have, be, hear, see, like, hate, know等。
I like English very much.
不说I am liking English very much.
I often hear him sing in the next room.
不说I am hearing him sing in the next room.
5. always, constantly, forever常与进行时连用，表示厌烦，赞扬等感情色彩。
He is always forgetting to bring his text book. (批评)
He is forever thinking of others. (赞扬)
You are constantly making the same mistake.
6. 现在进行时与一般现在时的区别：前者侧重在描述动作暂时的情景，状态的持续，后者侧重在说明事理，陈述一个事实。
She is speaking English.
She speaks English every day.
7. 有些瞬间动词用现在进行时代表将来，“即将……”。
The train is arriving in two minutes.
He is coming back tomorrow.
(六)过去进行时
表示过去某一时刻，或某一阶段正在进行的动作，由was/were+ doing构成，句子中往往有过去的时间状语，代表过去的一个时间点，如：this time yesterday, at eight last night, at that time, then等，或用句子表示时间，像：when I got home等。
What were you doing at eight last night?
When I got home, mother was cooking.
What were you doing when I telephone you?
As she was reading the newspaper, Granny fell asleep.
过去进行时的各种要求及用法完全同现在进行时，只不过am/is doing改成was doing; are doing改成were doing.
(七)现在完成时
1. 由have/has(单数第三人称作主语)+ 过去分词构成，现在完成时的使用有两种情况。
(1)过去做的事情，强调对现在有影响，和现在说话有关，想知道结果，句中没有过去的时间状语，如：
1)--Have you bought the book?
--Yes.
--When did you buy it?
--Last Sunday.
在这段对话中，买书是过去做的事，但和我现在说话有关，我想知道到现在为止，书究竟买到了吗?回答“买到了”之后，我又想知道买书的时间，这是一个过去买书的时间，应该用过去时提问或回答。再比如：
2)--Have you had your lunch?
--Yes.
--Where did you have your lunch?
--At school.
--What did you have for your lunch?
--Rice, meat and peas.
但是在高考试卷中有这样一道题：
--Where the recorder? I can't see it anywhere.
--I it right here. But now it's gone.
A. did you put, have put
B. have you put, put
C. had you put, was putting
D. were you putting, have put
答案是B。“Where have you put the recorder?”问话人的意思是我一直在找录音机，找到现在，暗含着(到现在)你到底把它放哪儿了?所以用了完成时。
(2)现在完成时所表示的动作从过去开始，持续到现在，也许还会继续下去。常用时间状语有：for, since引起的短语，so far, already, yet, just, today, now, recently, lately, this week, this month, this year, these days, during/in the last/past few years, It is the first time that从句中疑问词How long的句子中，还有ever, never, before等。
Great changes have taken place in China in the past ten years.
--How long has the film been on?
--It has been on for half an hour.
I prefer dumplings which have just been cooked.
I have lived here since I was a child.
另外，现在完成时在时间或条件状语从句中，代替将来完成时，即不用will/shall have done/been.
Don't get off the bus until it has stopped.
If you have finished reading the magazine before I leave, please give it back to me.
Once you have learned it, you will never forget it.
I won't go home until I have done the job.
2. 区别for与since引导的短语作时间状语。for+ 时间段，since+ 时间点。since+ 时间点，看下面一道题：
--How long have you been here?
-- .
A. For four o'clock B. Since four o'clock
C. Since four hours D. At four o'clock
正确答案是B
2)假如会议是从2点钟开始，一直开到现在4点钟，请看下列句子和图示。
The meeting has been on for two hours.
The meeting has been on since two o'clock.
The meeting has been on since two hours ago.
3. since与from的区别：since“自从……以来”，表示时间从一个点开始，延至到现在(在过去完成时中延至到过去)，句子常用完成时。from“从……以后”，并不表示截止时间，如果表示截止，应该是from…to(till)…，有from或from…to/till作状语，句子常用一般时态。如：
From then on he never spoke to me. (过去时)
Since then, he has never spoken to me. (完成时)
From the 1910s to the 1950s Hollywood was the film center of the world. (过去时)
It has been ten years since he left his hometown. (完成时)
I will do better from now on.
4. already与yet的区别：already用于肯定句，yet多用于否定句和疑问句。
He has already taken the medicine.
Has he arrived yet?
He hasn't arrived yet.
5. ever, never, once, twice等与完成时连用情况：
This is the best film that I have ever seen.
I have never seen a better film than this one.
Hangzhou is the most beautiful place that I have ever been(to).
I have never been to a more beautiful place than Hangzhou.
例1)和例2)意思相同；例3)和例4)意思相同。
例1)这是我所看过的电影当中最好的一部。
例2)我从来没有看过比这更好的电影。(含义是这部电影是最好的)
例3)杭州是我所去过的最美的地方。
例4)我没去过比杭州再美的地方。(含义是杭州是我所去过的最美的地方)。
--Have you ever been to the Great Wall?
--Yes, I have.
或--No, never.
--How many times have you been to the Great Wall?
--One/Twice/Several times…
6. 瞬间动词和延续性动词在完成时中的使用：
(1)表示能够延续的情况或动作的动词叫做延续性动词，如：live, study, learn, teach, work, be, have(有)，know, walk, sleep, wait等。这类动词在完成时中可与表示一段时间的状语，或连词、疑问词连用，如for, since, how long等。
(2)瞬间动词，也叫终止性、结束性动词，表示动作的结果，或表示短暂性、一次性的动作。如：close, leave, buy, join, become, begin, fall(掉下)，fall ill(病倒)，get to(know), come, go, see, hear, hear from, catch a cold等。这类动词可以用于完成时，但在一般情况下，不能加上表示一段时间的状语或疑问词，如：
He has left. (正) He has left for a week. (误)
He has been away for a week. (正) How long has he left?(误)
How long has he been away?(正)
When did he leave?(正)
但是在否定句中，瞬间动词也可以和表示一段时间的状语、连词连用，它的含义是好长时间没进行这个动作了，没进行此动作的状态就可以延续。如：
I haven't heard from my parents for a long time. 我有好长时间没收到父母来信了。
He hasn't left home for a week.
他有一个星期没出门了。
判断下列几组句子：
电影开演五分钟了。
The film has begun for five minutes. (误)
The film has been on for five minutes. (正)
这支钢笔我买了大约两年了。
I've bought the pen for about two years. (误)
I've had the pen for about two years. (正)
我从昨天晚上起就感冒了。
I've caught a cold ever since last night. (误)
I've had a cold ever since last night. (正)
瞬间动词和持续性动词的转换归纳如下：
leave-be away from
buy-have
borrow-keep
die-be dead
get up-be up
put on(上演)-be on
close-be not open
catch a cold-have a cold
fall ill-be ill
fall asleep-be sleeping
come back-be back
open-be open
join the Party be a Party member
be in the Party
join the club be a member
be in the Party
join the army be a soldier
be in the army
work work
begin to study (去掉begin to) study
learn learn
teach teach
come to be here/there或
get to + 地点--
arrive in/at be in/at+ 地点
reach
come
to know-know
get
7. 注意现在完成时在下列句型中的使用：
I have studied English for five years. 可转换成：It has been five years since I began to study English.
或It is five years since I began to study English.
He has been away for a week.
鯥t has been a week since he left home.
或It is a week since he left home.
It has been years since I enjoyed myself so much.
或It is years since I enjoyed myself so much.
注意：例1)have studied English在since后面转换成began to study English, 才能译作：
自从我学英语以来，已经有五年了。例2)has been away在since后面转换成left. has been away持续性的状态，与for短语连用，而在since后用瞬间动词left. 译作：他离开家有一星期了。例3)enjoy是延续性动词，在since后面译作“否定”，即我有几年没玩得这么高兴了。在上述句型中“It”指时间。
8. 区别下列表达的不同含义：
He has gone to Hongkong. (他已去香港，人还没回来，“go”瞬间动词)
He has come to Hongkong. (他已来香港，人还没回去，“come”瞬间动词)
He has been to Hongkong several times.
(他曾经去过香港几次，人回来了)
He has been in Hongkong.
(他曾经去过香港，不和for/since状语连用，则单纯表达经历=has been to)
He has been in Hongkong for a year.
(他去香港一年了，人还在香港has been in…+ for短语，不能用has gone + for短语)
注意：例2)have been(to)…去过或到过某地，可与once, twice, often, never, ever, many times, several times及疑问词how many times连用。但如果有具体的时间状语in 1992, last year, for the second time或疑问词when等，句子要用过去时，如：
I went to Hongkong in 1992.
--When did you go to Hongkong?
--Last year.
(八)过去完成时
1. 过去完成时的构成：had+ 过去分词。其用法与现在完成时相同，只是动作截止时间不同。
现在完成时截止到现在，或还要继续下去，与现在事情有关；过去完成时截止到过去某时间点，与过去事情有关，区别如下：
We haven't seen each other since we parted.
从分手到现在，我们就一直没见面。
Last Sunday I met a friend of mine. We hadn't seen each other since we parted.
“上个星期天我遇到了我的一个朋友，从分手我们就没见过面。”这一动作截止到上个星期天。
现在完成时可单独用，无时间状语，而过去完成时必须有上下文，有表示过去的时间点，才可用，如：
He has left. (正)
He had left. (误)
When I got home, he had left. (正)
He Tokyo for long.
A. has left B. has been away from
C. had been away D. had left
答案：B
2. 过去完成时的使用：
(1)表示过去某一时刻或动作以前已经完成了的动作，即“过去的过去”。可用by, before, when等介词短语或从句来表示，还可以通过上下文来表示截止的过去的某一时刻。如：
Marx had learned some English before he got to England.
By the first century the making of paper in some parts of China had become common.
When I got to the cinema, the film had been on for five minutes.
(2)表示由过去某一时刻起，一直延续到过去另一时刻的动作或状态，常和for, since构成的时间状语连用，如：
It rained yesterday after it had been dry for almost a year.
The modern bridge was completed last year.
The designers had planned it since two years before.
(3)用在主句谓语动词是过去时的间接引语(宾语从句)中。如：
He asked what had happened to you.
They talked about what they had seen and done in the big fire.
(4)通过上、下文表示：
They went to the organizer's office and there they discovered the mistake. The organizer had put Dr. P Baker's name on the list of speakers…
On her way home that night the lady found that she had lost the diamond necklace which was borrowed from one of her friends.
3. 当连词before, after, as soon as引导的从句所表示的动作与主句的动作前后紧接时，由于连词本身已说明两个动作发生的先后关系，主句和从句都可用一般过去时表示，当然用过去完成时也可以。
After he locked the door, he left the house.
He turned off the lights before he left the lab.
He called me as soon as he arrived.
4. 过去完成时用于一些固定句型中：
(1)hardly…when/before 刚一……就……
He had hardly eaten the last mouth when he was back to his study. (句子没倒装)
Hardly had he eaten the last mouth when he was back to his study. (句子倒装)
(2)no sooner…than… 刚一……就……
I had no sooner put down my things than the telephone rang. (句子没倒装)
No sooner had I put down my things than the telephone rang.
(句子倒装)
(3)现在完成时和过去完成时都用于下面句型中。
the first
the second time that…
It/That is … 现在完成时
the last
the first
the second time that…
It/That was … 过去完成时
the last
在上面结构中，主句是is，定语从句用现在完成时；主句是was, 定语从句用过去完成时。如：
It is the first time that I have left home.
It was the first time that I had left home.
5. 在过去完成时中瞬间动词和延续性动词的要求同现在完成时，如：
The motor-bike that he had bought for two years was stolen the night before. (误)
鯰he motor-bike that he had had for two years was stolen the night before. (正)
He had joined the army for three years before he went to college. (误)
鯤e had been in the army for three years before he went to college. (正)
6. 在原本打算，实际未做成的结构中，原本打算做的动作为过去完成时态。(过去的过去)常用动词有：had wanted, had thought, had hoped, had expected, had meant, had planned等。如：
We had hoped to catch the 9∶30 train, but found it was gone.
I had meant to join the party, but I was too busy in the office then.
He had wanted to help us, but couldn't get here in time because of heavy traffic.
7. 过去完成时在下列句型中的使用：
It had been+ 时间+ since… 如：
My brother returned home yesterday. He had been away from home for two years.
鯩y brother returned home yesterday. It had been two years since he left home.
或 It was two years since he had left home.
而It was two years since he left home是错误的。
Grandma said that it had been fifty years since they arrived in the U. S. A.
或Grandma said that it was fifty years since they had arrived in the U. S. A.
现在完成时也用于此句型，两种时态在这个句型中的使用归纳如下：
It has been + 时间+ since…过去时…
It is + 时间+ since…过去时…
It had been + 时间+ since…过去时…
It was + 时间+ since…过去完成时…
8. 过去完成时在时间、条件状语从句中代替would/should have done. 即过去将来完成时，当主句为过去将来时的时候。如：
John told me that when he had finished his job, he would join us in picnic.
The experiment showed that once it had been frozen, it would not be smelt.
(九)现在完成进行时与现在完成时的区别
现在完成进行时由have(has)been+ 现在分词构成，表示从过去某一时刻开始到现在，一直在进行的动作，可能刚刚终止，也可能继续下去，强调动作的延续性，有些词如：work, study, live, teach等，用现在完成进行时与用现在完成时意思差不多，如：
I have taught here for ten years.
I have been teaching here for ten years.
但多数情况下两个时态意思不同，现在完成时强调动作的完成(结果)或者表示过去发生的事情对现在造成的影响，而现在完成时则强调动作的延续性，并无对事情总结的含义。一般不和already, yet, never, ever, just等这样的时间状语连用。如：
I have been waiting for his reply for more than three months(动作延续性)，but I haven't heard from him yet. (结果)
He has been writing a story since last night. (动作)
He has already completed his story. (结果)
My shoe has been pressing against my foot.
我的鞋一直挤脚。
--Why do you look worried?
--I have been waiting here for half an hour, but he doesn't appear.
It has been raining for about two hours.
但是在否定结构中一般用现在完成时。对比：
I have been writing the story since last Sunday.
I haven't written any story since last Sunday.
(十)过去完成进行时
过去完成进行时的构成由had been+ 现在分词，其用法与现在完成进行时相同，只是用于过去的场合，从过去某一时间开始一直延续到过去的另一个时间，可能刚刚结束，也可能继续延续，如：
1)It had been raining since early morning. They had to stay at home.
2)Paula showed me the story that she had been writing.