Go to sleep.
I want to sleep.
I couldn't sleep.
You should sleep.
I can't sleep well.
I'm trying to sleep.
Don't go back to sleep!
I have to get some sleep.
Did you have a good sleep?
Don't lose sleep over that.
I had a good night's sleep.
I want to sleep a little more.
I want to sleep a little longer.
The baby cried herself to sleep.
The baby cried himself to sleep.
This bed is too hard to sleep on.
I was tired, but I couldn't sleep.
I should go home and get some sleep.
It was so cold that I couldn't sleep.
You were talking in your sleep last night.
He was just on the verge of going to sleep.
He looked refreshed after a good night's sleep.
I couldn't sleep well because it was noisy outside.
He couldn't sleep because of the noise outside his window.
Last night was very hot and muggy, so I didn't sleep so well.
Last night was very hot and muggy and I didn't sleep very well.
The children were so excited after the party that they couldn't sleep.
It's only when I can't sleep at night that the ticking of the clock bothers me.