用法灵活的until

2020-09-10 07:22王化清
初中生学习指导·中考版 2020年7期
关键词:上床睡觉句首否定句

王化清

until一词在中考试题中出现频率较高,且not...until又是一个重点句型,所以,希望同学们一定要掌握它的用法。

一、从含义上讲,可与时间、地点连用。如:

He worked until midnight. 他一直工作到午夜。

The boy didn’t go to bed until ten o’clock. 这个男孩直到10点才上床睡觉。

Go along this street until the bridge,you’ll see the hospital.

沿这条街道往前走直到那座桥,你就会看见那个医院。

二、从词性上讲,可作介词或连词。如:

Most of the shops are not open until nine o’clock. 大多数商店直到9点才开门。(作介词)

He didn’t wake up until the class was over. 他直到下课才醒来。(作连词)

三、从句型上讲,可用于肯定句,也可用于否定句。

1. 用于肯定句表示主句动作或状态结束。如:

The woman worked in the factory until 2005. 这个妇女在那个工厂一直干到2005年。(表示在2005年“work”这个动作结束)

He had been in Jiangsu for ten years until he moved to Beijing. 他在搬到北京之前在江苏已经住了10年了。(表示“他”在江苏居住了10年后,搬到北京)

2. 用于否定句,构成not … until句型,表示主句动作直到until所表示的时间才开始发生,即表示动作的起点。如:

He didn’t go to bed until the TV play was over.

他直到电视剧结束才上床睡觉。(当电视剧结束时,“上床睡觉”这个动作才开始)

The student won’t go home until he finishes his homework. 那个学生直到完成他的家庭作业才回家。(只有当他完成作业时,“回家”这个动作才开始)

温馨提示:

(1)until用作连词引导时间状语从句时,从句的动作若发生在将来,不要用将来时,而要用一般现在时。如:

I won’t do that until you come back. 在你回来之前,我不会做那件事。

(2)until也可放在句首。另外,当not until位于句首时,主句的主、谓语需要倒装。如:

Not until the bell rang did the students stop talking. 直到铃声响起,学生们才停止讲话。

四、until与after,before,as soon as,when之间的转换。

1. 与引导时间状语(从句)的after之间的转换,构成主句否定,until直接替换after。如:

The scientist had supper after he finished the work at midnight.→ The scientist didn’t have supper until he finished the work at midnight.

He went to school after 8 o’clock. → He didn’t go to school until 8 o’clock.

2. 与引导时间状语(从句)的before之间的转换。

(1)当before是介词时,必须确保谓语动词是否定形式才能用until替换before,否则句意发生变化与原句不符。如:

Most of the shops are not open before nine o’clock. → Most of the shops are not open until nine o’clock.

(2)当before是连词时,原主句(肯定形式)变为until引导的从句,原从句变为主句,并要構成否定形式。如:

Before you cross the street,the lights must turn green. → You can not cross the street until the lights turn green.

但如果主句原来是否定形式,只需把before变为until即可。如:

I didn’t leave before my brother came. → I didn’t leave until my brother came.

3. 与引导时间状语(从句)的as soon as / when之间的转换,主句变为否定句,until直接替换as soon as / when。如:

I’ll tell him the news as soon as he comes back. → I won’t tell him the news until he comes back.

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