by the time用法

By the time 用法详解

•by the time意为“到……时候（为止）”，是一个介词短语，在句中经常起连词作用，引导时间状语从句。它的主要用法如下：

• 1. 如果从句中的谓语动词是一般过去时，那么主句中的谓语动词通常用过去完成时，表示“截止到从句动作发生时，主句动作已经完成，即过去的过去”。例如：By the time he returned home，the rain had stopped.

•By the time I got to the station，the train had already gone。

• 2. 如果从句中的谓语动词为一般现在时/或现在完成时（表示将来），那么主句中的谓语动词常为将来完成时，表示“截止到将来某一时间为止，主句动作将已经完成”。

By the time you get back，I shall have finished the work.

•By the time I graduate next year, I will have lived here for 5 years.

•By the time of next term , we will have learned 3000 words.

• 3. 如果主句动作不强调已经完成，只是说明某个时候的状况，（主句是be的系表形式或者是表示像know, find, believe等表示认知的持续性动词，则往往用一般时态，不用完成时态。）此时主句不用完成时，而应根据实际需要选用适当的时态，此时by the time相当于when。例如：

•He was out of breath by the time he reached the top.

By the time the bus came，so many people were waiting that it was a free fight to get on it.

公共汽车来的时候，等车的人很多，成了一场挤车的混战。

•By the time he went abroad, he was fourteen.出国那年他14岁。

•By the time the war was over , death and suffering were to be seen everywhere.

•在战争结束的时候，到处可见死亡和饥饿。这里没有“死亡和饥饿”已经完成的意思，只是描述当时这个时间点的状况。所以用过去时。

•巩固练习：

• 1. （2005天津卷）By the time Jane gets home，her aunt _____for London to attend a meeting.

A. will leave

B. leaves

• C. will have left D. left

• 2. By the time you have finished this book, your meal ___ cold.(2012四川卷)

• A. gets B. has got C. will get D. is getting

• 3. （2009北京卷）When I talked with my grandma on the phone，she sounded weak，but by the time we _____ up，her voice had been full of life.

A. were hanging

B. had hung

• C. hung D. would hang

• 4. ―Did you see Xiao Li at the party？

―No，_____by the time I arrived.

A. she’d left

B. she’s left

• C. she was left D. she must leave

5. By the time I saw the angry expression on his face，I_____ what I had to face.

A. knew

B. have known

• C. would know D. had known

6.（2008四川卷）The telephone_____，but by the time I got indoors，it stopped.

A. had rung

B. was ringing

C. rings

D. has rung

•7.（2008山东卷）By the time he realizes he _____into a trap，it’ll be too late for him to do anything about it.

A. walks

B. walked

C. has walked

D. had walked

情态动词用法总结如下表

学法提炼

If they _________ to do this work, he might do it some other way.

A. were

B. should

C. will

D. can

2. I was told yesterday that the company _________ me to Rome next week for a business conference.

A. should have sent

B. were going to send

C. should be sending

D. should send

3. Let’s take a walk, ________?

A. will we

B. don't we

C. do we

D. shall

we

4. He was a good swimmer so he _________ swim to the river bank when the boat sank.

A. could

B. might

C. should

D. was able to

5. I went to the doctor's yesterday, I had to wait for half an hour before he ________ see me.

A. can

B. may

C. might

D. could

6. ---- _________ this book be yours? ---- No, it ________ not be mine. It ________ be his.

A. Can, must, may

B. May, might, must

C. Can, may, must

D. Must, can, may

7. ---- "We didn't see him at the lecture yesterday.”

---- “He _________ it.”

A. mustn't attend

B. can't have attended

C. would have not attended

D. needed have attended

8. They _________ the plane, or perhaps they have been prevented from coming for some reason.