to sleep

• 该睡觉了。

  It's time to go to sleep.

• 你几点钟睡觉?

  What time do you go to sleep?

• 一夜没睡觉

  stay up all night

• 哄小孩睡觉

  lull a child to sleep

• 他睡觉很惊醒。

  He's a light sleeper.

• 那天夜里她怎么也睡不着觉。

  That night she just couldn't get to sleep.