状语从句时态

Question

告诉我主句用什么时态时，从句对应用什么时态……

谢……

Answer 1

从句与主句的时态不一定要一致。在状语从句中有一个规则是“主将从现”，即主句是将来时，则从句要用一般现在时表示将来。如果从句表示的是客观事实，则从句还是要用现在时；状语从句又分为条件状语从句和时间状语从句，让步 状语，和地点状语从句。例如在
if 引导的条件状语从句中，如果从句谈论的是一个有可能发生的事实及其产生的相关的结果，主句用一般将来时态，从句用一般现在时态。

Answer 2

时间状语从句:

连接时间状语从句的连接词有:

(1) 连词：when, while, as. 它们都表示当…时候的意思。如果主句和从句的动作同时发生且都是进行时
态，只用while, as. 其他情况下when, while, as通用。

1 When he came in, I was listening to the radio．

2 As I was wandering in the street, I met her.

3 While (as) I was watching TV, my mum was cooking in the kitchen.

(2) 连词before, after, since, until(till). 当他们表示时间时，他们既是介词又是连词。

{ He usually drinks a cup of tea before he goes to school.
连词
He usually drinks a cup of tea before going to school.
介词
{
He usually drinks a cup of coffee after he comes back from school.
连词
He usually drinks a cup of coffee after coming back from school.
介词
{

I have lived in Dalian since my son was born in 1999.
连词
通常情况下，主句用现在完成时，从句用一般过去时。
I have lived in Dalian since 1999.
介词

{
I will wait here until(till) you finish your job.
连词
I will wait here until(till) 8pm.
介词

(3) 词组：as soon as

{ I will tell him as soon as he comes back.
As soon as she finishes her homework, she will play tennis.
通常情况下，主句用一般将来时，as soon as 引导的从句用一般现在时。
[思路分析]
见下
[解题过程]
连词when, before, after, if引导的状语从句要特别注意其时态。
1．当主句的谓语动词是一般将来时时，从句要用一般现在时。如：
The boy will be a writer when he grows up.这个男孩长大后将成为一名作家。
I won’t go to school if it rains tomorrow.如果明天下雨我就不去学校。

2．主句的谓语动词是情态动词+动词原形时，从句的谓语动词也用一般现在时。如：
When the lights are red, the traffic must stop.红灯亮时，车辆必须停下。

3．主句是祈使句时，从句也要用一般现在时。如：
Please don’t go to bed before you finish your homework.在完成作业之前，请不要休息。

4．主句谓语用一般过去时时，从句也要用一般过去时。如：
They talked about the party after people left.人们离开后，他们谈论这次晚会情况。
在if、unless等词引导的条件状语从句，when、till/until、as soon as、the time等词引导的时间状语从句，以及the more...the more结构引导的程度状语从句中，当主句中的动词用一般将来时，从句中的动词通常用一般现在时表示将来时间。有时，也可以在从句中用现在完成时表示将来某一时刻前已完成的动作。