题目

until的用法
until前后时态,请把几种都列出来.

提问时间：2020-08-02

答案

一、 介词until
作介词的until 的英文解释是up to a specified time (直到某一时刻)或up to the time of a specified event (直到发生某事).但注意观察下列句子,我们还可留意到until 在具体运用中的细微之处.
1. 用于肯定句中：
1) It may last until Friday. 这可能要延续到星期五.
2) He will be working until 5 o'clock. 他将一直工作到五点钟.
3) She was a bank clerk until the war, when she trained as a nurse. 她战前是个银行职员,战时受训当了护士.
不难看出until 用于肯定句中,表示句子的动作一直持续到until短语所表示的时间为止,即表示动作的终点.一般可译为“直到……时(为止)”或“在……以前”.在这种用法中,句子的谓语动词必须是持续动词(非瞬间动词),如live, wait , last, love, like, stay, work, continue 等.
2. 用于否定句中：
1) The secret was never told until after the old man's death. 这个秘密在老人去世后才说出来.
2) Don't open it until your birthday. 等到你过生日那天再打开.
3) She didn't sleep until eight. 她八点钟才睡觉.
不难看出until用于否定句中,表示句子的动作直到until短语所表示的时间才开始发生,即表示动作的起点.一般译为“直到……才”或“直到……之前(……还不)” .
二、 连词until
以同样的方式分析作连词的until的用法.作连词用的until的英文释义是up to the time when(直到……时为止).
1. 用于肯定句中：
1) Heat can be conducted from a hot body to a cooler one until both are at the same temperature.热可以从一个热的物体传到一个较冷的物体,直到两者温度相同为止.
2) Continue in this direction until you see a sign. 一直朝着这个方向走就会看见指示牌了.
3) He ran until he was breathless. 他一直跑到气喘吁吁才停下.
不难看出,作连词的until用于肯定句中,表示主句的动作一直持续到从句动作发生或状态出现时为止.一般可译为“……直到……为止”.在这种用法中,主句的谓语动词必须是持续动词(非瞬间动词),如live, wait , last, love, like, stay, work, continue 等.
2. 用于否定句中：
1) I hadn't realized she was foreign until she spoke. 她不说话我还一直不知道她是个外国人.
2) I won't stop shouting until you let me go. 你不放我,我就一直喊叫.
3) Among the great mathematicians there are about as many who showed mathematical talents in childhood as there are those who showed none at all until they are older. 在伟大的数学家中,童年就显露数学才华的人和直到相当年龄才显露才华的人差不多一样多.
不难看出,作连词的until用于否定句中,表示主句的动作在从句的动作发生之前尚未发生,或者说主句的动作在从句的动作发生之后才开始.一般可译为“直到……才”.