解密动词时态
动词时态常常是高考的必考点，你能运用自如吗？笔者总结了以下七个方面，帮助你正确运用动词时态。
1． 时态的替代现象
（1） 在时间、条件和让步状语从句中常用一般现在时或现在完成时替代一般将来时；用一般过去时或过去完成时替代过去将来时。
The harder you study, the better results you will get.
I won’t go swimming if it rains.
Don’t get off the bus until it has stopped.
He said he would call on me if he had time.
(2) 表示去向的动词或起止性动词（come, go, leave, arrive, start, move, sail, fly, take off, get off, travel, return, begin, stop, open, close, end, stay等）可用一般现在时表示按时刻表将要发生的动作；现在进行时表示预定的近期所发生的动作；过去进行时表示过去计划、安排好的将来动作。
The train leaves at 4:30 p.m.
I’m leaving for Beijing tomorrow.
I was told the plane was taking off soon.
(3) here, there, now, then等开头的倒装句要用一般现在时替代现在时替代现在进行时。
Look! Here comes the teacher.(=The teacher is coming.)
Listen! There goes the bell. (=The bell is ringing.)
(4) before, after, asoon as 本身“先、后”时间明确，可用一般过去时替代过去完成时。
He (had) left before I arrived.
After I (had) finished my homework, I went to bed.
(5) 若干连续动作，如果其顺序非常清楚，又不强调先后，或用then,and,but等词连接时，无需用过去完成时。
He stood up, went out of the classroom and soon disappeared in the street.
My aunt gave me a watch and I lost it.
(6)think, want, suppose, guess, expect, hope, wish, intend, mean, plan等表示愿望、打算的动词，可用一般过去时替代一般现在时，过去完成时替代一般过去时，表示现在或过去未能实现的打算、愿望、意图等。
I wanted to stay with you, but I have an important meeting to attend.
He had hoped to arrive time, but his car broke down.
(7) make sure (certain), see to it, mind, care, matter, so long as 等后接宾语从句时，从句用一般现在时替代一般将来时。
So long as he works hard, I don’t mind when he finishes the experiment.
2． 时态呼应原则
含宾语从句的主从复合句，若主句谓语是现在时或将来时，从句谓语可用任何所需要的时态；若主句谓语是过去时，从句谓语要用过去的某种时态（但客观真理、科学事实、格言警句等仍用一般现在时）。
The teacher said he was satisfied with us.
I learned that the earth goes around the sun when I was in primary school.
3． 现在完成时与一般过去时的区别
现在完成时强调过去动作对现在的影响，一般过去时表示过去动作的事实。
I saw the film last week.（看电影是上个星期的事，与现在无关）
I have seen the film before.（强调了解电影内容，现在无需再看）
（2）现在完成时表示过去开始的动作延续到现在，一般过去时表示过去延续了一般时间的动作已停止。
He was a soldier for 3 years.他曾当过三年兵。（现在退伍了）
He has been a soldier for 3 years.他已当兵三年了。（现在还在服役）
(3) 没有包括“现在”在内或不是截止到“现在”的时间状语不能与现在完成时连用。
China was poor in the past.（in the past不包括“现在”）
Great changes have taken place in China in the past 20 years.（是算至“现在”为止）
4． 过去完成时不能孤立使用， 它必须以过去某一时间为基点，即“过去的过去”，因此只有在和过去某时或动作相比较时才用到它
He had read it.（此句错误， 因为无时间比较，得不出read是发生在“过去的过去”）
He said he had read it.（此句正确，read发生在said之前，即“过去的过去”）
5. 短暂性动词的肯定式不能与时间段连用
I have received it for a wek.（此句错误，因为receive是短暂性动词）
I have had it for a week.（此句正确，因为have是延续性动词）
I haven’t received it for a week. （此句正确，因为是延续的）
6. will/shall do, be going to do, be to do, be about to do与 be doing /do的区别
（1） shall/will do表示事先未经考虑，而是临时起意的打算、计划，没有主观性，是纯粹的将来动作。这种用法常见于会话中乙听了甲的话之后作出的反应。
I shall/will not be free tomorrow.
He will arrive here this evening.
---Where is the telephone book?
---I’ll go and get it for you .
---You’ve left the light on.
---Oh, so I have. I’ll go and turn it off.
（2） be going to do表示现在打算最近或将来要做某事，这种打算往往经过事先考虑，甚至已做了某种准备；也可以表示某种可能性，即有迹象表明要发生某事。
He is going to spend his holidays in London.
It is going to rain soon.
(3) be to do 表示按预定计划、安排即将发生的动作，这个动作发生的时间一般不会很远；还可表示吩咐、要求、命令或禁止他人做某事，或某事注定要发生。
The new bridge is to open to traffic in three days.
You are not to bring any mobile communication means into the exam room.
You are to stay home until your mother comes back.
(4)be about to do表示即刻就要着手进行的动作，后面不能接时间状语或状语从句。
Autumn harvest is about to start.
The ship is about to leave.
（5）be doing/do强调在近期按规定、计划或安排要发生的事。
Do you get off at the next stop?
The plane takes off at 11:00 a.m.
Are you staying here till next week?]
7.七种特定时态
（1） 常见的不确定的时间状语，如：lately,recently, just, already, yet, up to now, till now, so far, these days, ever since, since then, for(during, over, in) the past (last, recent)…常与现在完成时连用
He has been in the lab over the past two weeks.
（2） 表示“第几次做某事”或在“It is the best (worst, only , most interesting)+名词+that”结构中，that从句用现在完成时。若is改用was，则用过去完成时。
This (It) is my first time that I have visited China.
This (It) is the most interesting film I have ever seen.
That(It) is the only book that he has written.
That(It) was the second time that she had seen her grandfather.
（3） by , by the time 表示“在。。。之前，不迟于。。。”常与完成时连用。
By the time you reach the station, the train will have left.
By the Tuesday, I will have got ready for the exams.
（4） since表示“自从。。。以来”，主句用现在完成时，从句用一般过去时。
I have lived here since I came here.
（5） 用于hardly/scarely…when; no sooner …than句型中，主句用现在完成时，从句用一般过去时。
I had hardly finished my work when he came to see me.
No sooner had I arrived home than the telephone rang.
（6） “祈使句+and/then/or+陈述句”结构中，陈述句谓语用一般将来时。
Use your head and you will find a way.
（7） when（这时突然）用作并列连词，前句常用过去进行时或be about to do，后常用一般过去时。
I was walking along the river when I heard someone crying for help.
He was about to go to bed when the telephone rang.
责任编辑：李芳芳