VOA一分鐘英語：Until 和 by 的用法

本集 “一分鐘英語” 介紹用來說明動(dòng)作發(fā)生時(shí)間的詞語 —— “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” 表示某事在未來的某個(gè)時(shí)間點(diǎn)前持續(xù)發(fā)生；“by” 表示某事在未來某個(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” 用來表示 “在未來某個(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.