sleep ²

作“睡眠”解的 sleep 是个不可数名词。some 与不可数名词连用是很常见的（见 some $^{3}$ ）：

1. He didn't get much sleep. 他睡眠不足。

2. He reckons he only needs six hours sleep a night. 他认为他每夜只需要六个小时的睡眠。

3. I must get some sleep — I'm exhausted. 我得睡一会儿——我已筋疲力尽了。

4. As I was reading I went to sleep. 当我读书的时候睡着了。

但是,当指“一次睡眠”“一段睡眠时间”时,则可以说 a sleep:

1. I think I'll go upstairs and have a sleep. 我想我要上楼睡一会儿。

2. I was awakened from a sound sleep. 我从熟睡中被吵醒了。