2015年专四语法知识指导：时态

Tense 时态
四级常考的重点时态
英语共有16种时态，在CET-4语法测试中，时态是⼀个常测项⽬，也是⼀个必测项⽬。

测试重点有：现在完成时，现在进⾏时，现在完成进⾏时，将来完成时，过去完成时，过去进⾏时，⼀般将来时。

利⽤时间状语的信息提⽰
时态与时间状语之间存在⼀定的呼应关系。

时间状语可以决定时态。

时间状语常出现在句⾸或句尾，有时也出现在谓语动词前后。

标志完成时态的时间状语
Ever since, since, since then, by then, by now, by the end of, by the time, when, before, for, sofar, up till now, for, in the past few days, in the past / last few years
标志进⾏时态的时间状语
Now, right now, at the moment, yesterday afternoon, last Sunday, just now, this timetomorrow
标志将来时态的时间状语
Tomorrow, tomorrow morning, soon, next, in two days, in the year 2050, in 10 years’ time,some day in the future,
Examples
1. Ever since the family moved to the suburbs last year, they ____ better health.
A. could have enjoyed
B. have been enjoying
C. had enjoyed
D. are enjoying
2. Since then, I ____ the mail.
A. am expecting
B. have been expecting
C. expected
D. was expecting
3. You should have put the milk in the ice-box; I expect it ____ undrinkable by now.
A. became
B. had become
C. has become
D.become
4. When he hurried to the airport, he found, to his great disappointment, his ticket andpassport ___ at home.
A. were left
B. had left
C. to have been left
D. had been left
5. By the time you get to Beijing tomorrow, I ___ for Shanghai.
A. am leaving
B. shall have left
C. will leave
D. have already left
6. It is reported that by the end of next month the bridge ____.
A. will be built
B. has been built
C. will have been built
D. will have built
特定结构和句型中的时态
1.This(That/It) is the first (second…) +名词+定语从句
This(That/It) is the only (last) +名词+定语从句
This(That/It) is the +形容词级+名词+定语从句
Examples
This is one of the rarest questions that ___ at sucha meeting.
A. has ever been raised
B. is raised
C. are raised
D. have ever been raised
There was a knock at the door, it was the second time someone ___ me that evening.
A. had interrupted
B. would have interrupted
C. to have interrupted
D. to be interrupted
2.It is /has been + 时间段 since +从句(⼀般过去时)
It will be +时间段before +从句(现在时)
It was +时间段before +从句(⼀般过去时)
It is likely /unlikely that +从句(⼀般将来时)
Examples
It ___ 2 weeks since she fell down the stairs, but you can still see the bruises.
A. was
B. is
C. will be
D. were
Last night a man escaped from prison. It was a long time ____ the guards discovered what hadhappened.
A. since
B. when
C. before
D. that
3.“祈使句+and”结构中, and 引导的并列分句谓语动词⽤⼀般将来时。

Hardly/scarcely…when, no sooner…than句型中主句常⽤过去完成时，从句⽤⼀般过去时。

Examples
___ when she started complaining.
A. Not until he arrived
B. Hardly had he arrived
C. No sooner had he arrived
D. Scarcely did he arrive
Turn on the radio or open a magazine and you ___ advertisements showing happy andbalanced families.
A. are often seeing
B. often see
C. have often seen
D. will often see
副词的位置
在时态测试中，根据某些副词在句中的特殊位置这⼀特点，也有助于判断选项的正误。

频率副词always,often, frequently, seldom, never, ever, usually , rarely, occasionally, no sooner, hardly,scarcely等以及just, shortly等其他副词必须放在助动词、情态动词或be动词与实义动词之间。

在省略结构中，这些副词必须放在助动词、情态动词或be 动词之前。

Examples
We ___ our breakfast when an old man came to the door.
A. just have had
B. have just had
C. just had had
D. had just had
San Francisco is usually cool in the summer, but Los Angeles ____.
A. is rarely
B. rarely is
C. hardly is
D. is scarcely
时态⼀致
从句谓语动词时态受主句谓语动词时态限制，主句谓语动词是现在时或将来时，从句时态根据需要选择;主句谓语动词是过去时，从句通常也⽤过去时。

这是四级语法测试重点。

如：主句谓语动词是过去时，则
1)主从句动作同时发⽣，从句did 或was/were doing.
2) 从句动作发⽣在主句动作之前，从句had done.
3)从句动作发⽣在主句动作之后，从句would do.
Examples
After searching for half an hour, she realized that her glasses ___ on the table all the time.
A. had been lying
B. had been lain
C. have been lying
D. were lain
Exception (例外)
如果从句中所表⽰的是⼀个客观事实或科学真理，从句谓语动词不受时态原则限制，只能(永远)⽤⼀般现在时，通常根据常识就可以确定答案。

Our teacher has a strict rule. She said yesterday that all the students ___ to class on time.
A. came
B. might come
C. must come
D. must have come。