2015年衛(wèi)生類職稱英語考試語法知識：

1、由as soon as, immediately, directly, instantly, the moment, the second, the instant, the minute, the while 等引導的時間狀語從句。這些連詞都表示“一……就"。例如：

I will go there directly I have finished my breakfast.

The moment I heard the news, I hastened to the spot.

【注意】hardly(scarcely, rarely)…when / before, no sooner…than相當于as soon as之意。主句用過去完成時，從句用一般過去時。當hardly, scarcely, rarely和no sooner位于句首時，主句應用倒裝語序。例如：

He had no sooner arrived home than he was asked to start on another journey.

No sooner had the sun shown itself above the horizon than he got out of bed to commence work.

由by the time引導的時間狀語從句。

在一般情況下，如果從句的謂語動詞用一般過去時，主句的謂語動詞用過去完成時;如果主句的謂語動詞用一般現(xiàn)在時，主句的謂語動詞用將來完成時或?qū)�來進行時。例如：

By the time you came back, I had finished this book.

By the time you come here tomorrow, I will have finished this work.

By the time you come back tomorrow, I will be having lessons in class.

By the time you arrived home, I will be studying in this university.

2、由each time\every time\next time/last time/every time/the first time,和whenever/no matter when引導的時間狀語從句。例如：

Each time he came to Harbin, he would call on me.

Whenever that man says"To tell the truth", I suspect that he's about to tell a lie.

No matter when she says"to tell the truth", I suspect that he’s about to tell a lie.

3、由as long as和so long as引導的時間狀語從句。這兩個連詞表示“有多久……就多久"或者“只要"。如 　　You can go where you like as long as you get back before dark.

I will fight against these conditions as long as there is a breath in my body!

You can stay as long as 10 days.