342 时间从句
A 时间从句由下列表示时间的连词来引导：
| after |
immediately |
till／until |
| as |
nosooner…than |
when |
| as soon as |
since |
whenever |
| before |
the sooner |
while |
| hardly … when |
|
|
时间从句也可由 the minute，the moment 来引导。
用 when，as，while 的例句，参见第331节至第333节。
用 before 的例句，参见第195节B。
B 请留意，时间从句中不用将来时态或条件时态。
1 如将下列将来时态放入时间从句中，须将它变为一般时态。
一般将来时：
You'll be back soon．I'll stay till then．
你会很快回来，我一直等到那时。相当于：
I'll stay till you get back．
我一直等到你回来。
be going to 形式：
The parachutist is going to jump．Soon after he jumps his parachute will open．
跳伞运动员要往下跳。他刚跳之后不久，降落伞就会打开。
现在进行时用做一般将来时和将来进行时：
He's arriving／He'll be arriving at six．
他将在6点到。
但是：
When he arrives he'll tell us all about the match．
等他到了，他会好好给我们讲讲那场比赛。
Before he arrives I'll give the children their tea．
在他来到之前，我会给孩子们吃茶点的。
如进行时态表示某一行动在继续，则其完全可以用在表示时间的从句中：
Peter and John will be playing／are playing／are going to play tennis tonight．While they are playing（during this time）we'll go to the beach．
今晚彼得和约翰要去打网球。他们打球时，我们将去海滨。
2 在时间从句中，将来完成时变为现在完成时，将来完成进行时变为现在完成进行时：
I'll have finished in the bathroom in a few minutes．
我一会儿就用完浴室了。
The moment／As soon as I have finished I'll give you a call．
我一完事儿，就给你打电话。
3 在时间从句中，条件时态变为过去时态：
We knew that he would arrive／would be arriving about six．
我们知道他将在六点钟左右到。
We knew that till he arrived nothing would be done．
我们知道在他到来之前，什么都干不了。
但是，如 when 引导的是一个名词从句，后面可跟将来时态或条件时态：
He said，‘When will the train get in？'
他说：“火车什么时候进站？”相当于：
He asked when the train would get in．
他问火车什么时候进站。
C since 从句（参见第187与第188节）
since 从句后面常跟完成时态（另参见第188节）：
They've moved house twice since they got married．／Since they gotmarried，they've moved house twice．
他们结婚后已搬了两次家。
He said he'd lived in a tent since his house burnt down．
他说自从他的房屋被烧毁后，他就一直住在帐篷里。
It's ages since I sailed／have sailed a boat．
我未驾驶帆船已有好多年了。
I haven't sailed a boat since I left college．
自从我大学毕业后就没再驾驶帆船了。
D after 从句
after 从句之后常跟完成时态：
After／When he had rung off I remembered…
等他把电话挂断了之后，我才想起……
After／When you've finished with it，hang it up．
你用完了之后，请把它挂起来。
E hardly／scarcely… when，no sooner… than（另参见第45节）：
The performance had hardly begun when the lights went out．
Hardly had the performance begun when the lights went out．
演出刚开始就停电了。
这里可以用 scarcely 代替 hardly，但不常见。
He had no sooner drunk the coffee than he began to feel drowsy．
No sooner had he drunk the coffee than he began to feel drowsy．
他喝了咖啡没多一会儿，就犯困了。
He no sooner earns any money than he spends it．
Immediately he earns any money he spends it．
他钱一挣到手，就花光了。
注意 the sooner…the sooner 的用法：
The sooner we start，the sooner we'll be there．
我们动身得越早，到那儿就越早。 |
