VOA一分鐘英語(yǔ)：Until 和 by 的用法

本集 “一分鐘英語(yǔ)” 介紹用來(lái)說(shuō)明動(dòng)作發(fā)生時(shí)間的詞語(yǔ) —— “until” 和 “by”。雖然這兩個(gè)詞都可以譯成 “到……時(shí)”，但它們的用法卻不同。“Until” 表示某事在未來(lái)的某個(gè)時(shí)間點(diǎn)前持續(xù)發(fā)生；“by” 表示某事在未來(lái)某個(gè)時(shí)間或最后期限前發(fā)生。
 
Hi, guys! This is Kee from BBC Learning English. And today, I'm going to tell you the differences between until and by.
We use until to talk about doing something up to a certain point in time. If I say: 'I have to take care of my dog until 5pm', it means I will start taking care of my dog now and stop taking care of it at 5pm.
On the other hand, we use by to talk about doing something before a future time or a deadline. If I say: 'I have to finish an essay by 5pm', it means I can start any time, but I will make sure that at 5pm I have finished writing the essay. So, I may even finish it at 3pm or any time before 5.
So, we use until to describe doing something up to a certain point in time, and we use by to describe doing something before a future time or a deadline. 
 
用法總結(jié)
1 Until
Until is used to talk about doing something up to a certain point in time.
“Until” 用來(lái)表示 “在某個(gè)時(shí)間點(diǎn)之前，一直做某事”。
I have to take care of my dog until 5pm.
Until the rain stops, we can't go to the beach.
I will be working until this evening. We can meet for dinner after that. 
 
2 By
By is used to talk about doing something before a future time or deadline.
“By” 用來(lái)表示 “在未來(lái)某個(gè)時(shí)間或最后期限之前做某事”。
I have to finish an essay by 5pm.
The council expects the bridge to be finished by December.
By the time I come back, I want this room clean.