涉及狀語從句的幾種特定時態(tài)

1. “主將從現”原則

即若主句為一般將來時，時間和條件狀語從句通常要用一般現在時表示將來，而不能直接使用將來時態(tài)。如：

I’ll give her the telex when she comes. 她來時把電傳交給她。

I’ll return the book as soon as I have read it. 這書一看完我就送還。

He’ll have four years at university after he leaves school. 他中學畢業(yè)后要上四年大學。

2. since與完成時

since 引導時間狀語從句時，其主句通常要用現在完成時，有時也用現在完成進行時。如：

She has had another baby since I saw her last. 從上次我見到她以來，她又生了一個孩子。

He has grown an inch since I saw him. 我上次見到他以后他已長高了一英寸。

注：當主句為“It + be + 一段時間”時，則通常用一般現在時代替現在完成時。如：

It’s more than three years now since I saw her last. 我們已有三年多沒見面了。

 3. 特定句式的時態(tài)

由no sooner. . . than, hardly [scarcely]…when引出的時間狀語從句，其主句通常用過去完成時，從句通常用一般過去時。如：

Hardly had he arrived when she started complaining. 他剛到她就抱怨起來。

No sooner had he gone to sleep than the telephone rang. 他剛睡著電話鈴就響了。

We had no sooner set out than a thunderstorm broke. 我們剛出發(fā)就下起一陣雷暴。

No sooner had she agreed to marry him than she started to have terrible doubts. 她剛同意嫁給他她就開始產生可怕的疑慮。