英语的时态是靠动词的变化和时间状语来表达的。英语中的时态共有十六种，但是常考的或较常用的只有8种，而且重点测试完成时态。 要掌握英语的时态和语态，必须掌握好英语中的助动词(do, be, have)和时间状语这两个核心问题。
1、一般现在时
主要用来表示人、事物的现在状况和特点；表示经常或习惯性的动作，句子中常有often, always, from time to time 等时间状语； 表示客观规律和永恒真理等。
He usually goes to work at 7 o’clock every morning.
She has a brother who lives in New York.
The earth goes around the sun.
Guangzhou is situated in the south of China.
考点一：表示永恒的真理，即使出现在过去的语境中，仍用一般现在时。如：
I learned that the earth goes around the sun when I was in primary school.
考点二：在时间和条件状语从句中，代替一般将来时；常用的引导词有：
时间：when, until, after, before, as soon as, once, the moment/the minute, the day; 条件：if, unless, provided.
If he accepts the job, he will get more money soon.
考点三：在make sure (certain), see to it, mind, care, matter ＋宾语从句， 从句用一般现在时代替一般将来时。
So long as he works hard, I don’t mind when he finishes the experiment.
只要他努力工作， 我不介意他什么时候做完试验。
考点四：在the more… the more … (越……越……) 句型中, 若主句是一般将来时, 从句通常用一般现在时。
The harder you study, the better results you will get.
2、现在进行时
表说话时或目前一段时间内正在进行的活动：或表感情色彩，加强语气。与频率副词，如always，constantly，continually，again等连用表示说话人的某种感情色彩（赞叹、厌烦、埋怨等）。
We are having English class.
The house is being built these days.
The little boy is always making trouble.
考点一：在时间状语或条件状语从句中表示将来正在进行的动作。
Look out when you are crossing the street.
Don\'t wake him up if he is still sleeping at 7 tomorrow morning.
考点二： 表示在最近按计划或安排要进行的动作（这时多有表示将来的时间状语）。
Marry is leaving on Friday.
3、现在完成时
表示动作发生在过去，完成在过去，但强调与现在情况仍有联系，其结果或影响仍存在。现在完成时有一些标志性的时间状语：
考点一：for + 时间段；since + 时间点
They have lived in Beijing for five years.
They have lived in Beijing since 1995.
I have learned English for ten years.
考点二：常见的不确定的时间状语：lately; recently, just, already, yet, up to now; till now; so far, these days,
Has it stopped raining yet?
考点三：在表示“最近几世纪/ 年/ 月以来……”时间状语中，谓语动词用现在完成时。
in the past few years/months/weeks/days；over the past few years; during the last three months; for the last few centuries, through centuries; throughout history 等
考点四：表示“第几次做某事，”或在 “It is the best (worst, most interesting ) +名词 ＋that” 后面跟现在完成时。
This is my first time that I have visited China.
This is the most interesting film I have ever seen.
That is the only book that he has written.
4．一般过去时
表在过去某个特定时间发生且完成的动作，或过去习惯性动作，不强调对现在的影响，只说明过去。常跟明确的过去时间连用，如：yesterday; last week; in 1945, at that time; once; during the war; before; a few days ago; when, 注意：
考点一：used to + do，表示过去经常但现在已不再维持的习惯动作。to为不定式，后接动词原形。
be/become/get used to + doing，表示习惯于
He used to smoke a lot.
He has got used to getting up early.
考点二：在时间和条件状语从句中，代替过去将来时。
He promised to buy me a computer if he got a raise
5. 过去进行时
表示过去某个时间点或某段时间内正在发生的动作。
The boy was doing his homework when his father came back from work.
He was taking a walk leisurely by the lake when he heard someone shouted for help.
What were you doing at nine last night?
The radio was being repaired when you called me.
6. 过去完成时
表示过去某个时间之前已经完成的动作，即过去完成时的动作发生在“过去的过去”，句中有明显的参照动作或时间状语，这种时态从来不孤立使用 ( before, after, by, up till )
There had been 25 parks in our city up till 2000.
By the end of last term we had finished the book.
They finished earlier than we had expected.
考点一：用于hardly/scarcely...when; no sooner ...than 句型中，主句用过去完成时，从句用一般过去时。
I had hardly finished my work when he came to see me.
I had no sooner got into the room than it began to snow.
No sooner had I arrived home than the telephone rang. （注意主谓倒装）
考点二：表示“第几次做某事”，主句用过去时，从句用过去完成时。
That was the second time that she had seen her grandfather.
It was 3 years since we had parted。
考点三：动词hope, expect, think, intend, mean, want, suppose, plan 用过去完成时，表示未实现的愿望、打算和意图。
I had hoped that I could do the job.
I had intended to see you but I was too busy.
7. 一般将来时
表在将来某个时间会发生的动作或情况。常和tomorrow, next year, in 2008等表示将来的时间状语连用，其表现形式多达5种。
Beijing will host the 29th Olympic Games in 2008.
考点一：一般将来时总是用在一些时间状语从句或条件状语从句的主句中：
We will begin our class as soon as the teacher comes.
（主句用一般将来时，从句中一定要用一般现在时替代一般将来时。）
考点二：某些表示短暂性动作的动词如arrive, come, go, leave, start等，用现在进行时形式表示将来。
I am leaving for Beijing tomorrow.
考点三：“祈使句 + and/or + 句子”，这种结构中and后面的句子谓语用一般将来时。
Use your head and you will find a way.
考点四：“am (is, are) going to + 动词原形”，表示打算要做的事或可能要发生的事。
“am (is, are) about to + 动词原形”表示按照预定计划或打算准备着手进行的动作。
“am (is, are) to + 动词原形”表示必须、必然或计划将要做的事。
They are to be married in this May.
8、将来进行时
表将来某个时间正在发生的动作，或按计划一定会发生的事情。
I’ll be doing my homework this time tomorrow. 明天这会我正在写作业。
The President will be meeting the foreign delegation at the airport.
9、将来完成时
表在将来某时刻之前业已完成的事情，时间状语非常明显。
考点一：常用的时间状语一般用by+将来的时间。如：by the end of this year, by 8 o’clock this evening, by March next year以及由by the time…, before或when等引导的副词从句。
By the end of next month, he will have traveled 1000 miles on foot.
By the time you reach the station, the train will have left.
By next Tuesday, I will have got ready for the exams.
考点二：在时间和条件状语从句中，将来完成时则由现在完成时表示。
The children will do their homework the moment they have arrived back from school.
参考资料：http://post.baidu.com/f?kz=123811530
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