【问】 (a) She slept till(until) nine.
 (b) She didn’t sleep till(until) nine.
 句(a)与句(b)中的till(until)的含义是否相同?
 【答】 可以这样来概括till (until)的含义：介词till(until)用在肯定句中时表示动作的终点，用在否定句中时则表示动作的起点。
 She slept till(until) nine. =She stopped sleeping at nine.
 她一直睡到九点钟。
 She didn't sleep till(until) nine. =She started sleeping at nine.
 她九点钟才始开睡觉。
 请分析下列各例中的till(until)的含义：
 1. They talked till dawn. (Palmer)
 他们一直谈到天亮。
 2. She will be working till nine o'clock.
 她将一直工作到九点。
 3. I sometimes stay in bed until lunch time. (NCE 2)
 有时我在床上一直躺到吃午饭的时候。
 4. He's only staying until tomorrow evening. (Mansfield)
 他只停留到明天晚上。
 5. They did not return home till nine o'clock.
 他们九点钟才回家。
 6. I didn't know till now that you were ill. (Chambers)
 直到现在我才知道你病了。
 7. Until now I knew nothing about it. (ALD)
 直到现在我才知道这件事(在此之前我对此事一无所知)。