时态的呼应

英语中的时态呼应(the sequence of tenses)就是在主句时态为“非现在时”时，从句的时态必须与主句相呼应。其规则如下： 　　

1.主句谓语为现在时或者将来时态，从句中的谓语时态可以不受影响，即按照意思决定时态。如：

It is reported that they are building a new railway. 　　

Will you please tell us how you got to know it? 　　

2.如果主句谓语为过去时，则从句谓语的时态要做相应改变。 　　

(1)一般现在时改为一般过去时，如：

I don't know where they live. 　　

I didn't know where they lived. 　　

(2)现在进行时改为过去进行时，如：

He wants to know how you're doing. 　　

He wanted to know how you were doing. 　　

(3)现在完成时改为过去完成时，如:

I wonder if they have got a reply. 　　

I wondered if they had got a reply. 　　

(4)现在完成进行时改为过去完成进行时，如:

I know you have been worrying about us. 　　

I knew you had been worrying about us. 　　

(5)一般将来时改为过去将来时，如:

I hope she will find a job soon. 　　

I hoped she would find a job soon. 　　

(6)将来进行时改为过去将来进行时，如：

I think she will be playing golf this time on Sunday. 　　

I thought she would be playing golf this time on Sunday. 　　

(7)将来完成时改为过去将来完成时，如：

I expect he will have changed his mind by tomorrow. 　　

I expected he would have changed his mind by tomorrow. 　　

(8) 将来完成进行时改为过去将来完成进行时，如：

She will have been teaching in this university for 20 years by this summer. 　　

She told me that she had been teaching in this university for 20 years by this summer