until 和 till 词意相同，只是在正式文件或句首常用 until。它们既可作介词，又可作连词，引出时间状语或时间状语从句。
- Until when shall we wait for her? 我们要等到她何时为止？
- Please wait for her until (或 till) she comes back. 请等到她回来为止。
- She went on reviewing chemistry until (或 till) after 12 o’clock at midnight. 她持续复习化学直到半夜 12 点以后。（介词短语 after… 作介词 until 或 till 的宾语.）
- I did not find the letter until (或 till) this morning. 我直到今天早晨才发现这封信。
- She didn't finish reading your paper until after l turned back. 直到我回来以后她才读完你的论文。
- They were not supposed to arrive until 7 o’clock. 当时他们定于七点到达。
- Would you please not to read the listening comprehension script until after you have listened to the tape. 请你在听了磁带录音后再看听力理解材料。
- She has received few letters until (或 till) recently. 直到最近她才接到几封信。（注意 few 构成否定句。）
- Don't come and see me until (或 till) you have fulfilled your task. 直到你完成任务才能前来见我。
- I had not, till (或 until) then, thought out a good idea. 直到那时我才想出一个好主意。（注意 till then 插在谓语中间。）
- It was not until 10 o’clock (或 until the rain stopped) that we continued to work. 直到十点钟（或直到雨停止时）我们才继续工作。
- It was not until about 40 years ago that an electronic computer was invented which could lead to a rapid development of knowledge economy. 直到约 40 年前才发明了电子计算机，从而导致知识经济的迅速发展。
The letter is to be left here until (或 till) called for。这封信留在这里待领。