单元语法专练4

1、单元语法专练单元语法专练单元语法专练单元语法专练语法精讲-2-语法精练语法精讲时间状语从句1.when意为“当时”,引导的从句表示主句的动作和从句的动作同时发生或从句的动作发生在主句动作之前。注意:由when引导的时间状语从句,若主句的谓语动词是一般将来时,那么从句的谓语动词用一般现在时表示将来。2.while意为“当时,在过程中”,引导时间状语从句时,从句通常用进行时,如果主句和从句中的动作是两个同时进行的长时间动作或事件,那么主句也要用进行时。3.as意为“当时,一边一边”,引导时间状语从句时,常常表示主句和从句的动作是短时间的动作并且是同时发生。4.as soon as意为“一就”。例如

2、:As soon as we got there we began to work.我们一到那里就开始工作。5.before意为“在以前”,引导时间状语从句时,一般表示主句的动作发生在从句动作之前。单元语法专练单元语法专练语法精讲-3-语法精练语法精讲6.after意为“在以后”,引导的从句一般表示主句的动作发生在从句动作之后。7.since意为“自以来”,引导时间状语从句时,从句的谓语动词表示动作的起点,用一般过去时;主句的谓语动词表示动作开始以后延续至今,一般用现在完成时。如果主句表示目前的情况,可以用一般现在时。8.until/till意为“直到”,如果主句的谓语动词是延续性动词,主句和

3、从句都用肯定式。until/till表示“直到”。如果主句的谓语是短暂性动词,主句用肯定式,从句用否定式,即用not.until形式,表示“直到才”,这时until和till可用before替换。单元语法专练单元语法专练语法精讲-4-语法精练语法精练.用适当的连词填空1.He is about to leavewhenthe bell rings.2.Could we have a wordbeforeyou go to the meeting?3.As soon asI get to the airport,I will phone you to pick me up.4.Whenhe co

4、mes tomorrow,I shall ask where he has been.5.I saw her justasshe was getting off the train.6.He learnt to speak Germanwhilehe was in Berlin.7.How long have you stayed in this hotel?Not long,justsincethis Monday.8.Afterthe work was done,we sat down to sum up experience.9.I havent seen himsincehe move

5、d to the other side of the town.10.It was notuntilhe took off his eyeglasses that I recognized him.单元语法专练单元语法专练语法精讲-5-语法精练语法精练.单项填空( B )1.Mr Smith has a habit of taking a showerhe has breakfast.A.thoughB.beforeC.because D.since( D )2.Julie didnt leave officethe police arrived.A.howeverB.whenever C.whileD.until( C )3.Next month were going somewhere interesting as soon as the holiday.A.will beginB.has begunC.beginsD.is beginning( B )4.the dinner was all over,everyone helped wash the dishes.A.How B.WhenC.BeforeD.