I have a headache due to lack of sleep.

In the old days, people said 'Nenu,' which meant 'to sleep,' as we say today.

In the old days, people went to bed when night came.

You need a sleeping bag when you sleep in the mountains.

I will sleep now.

During summer vacation, I will go to the beach.

While he was taking a nap, I finished my homework.

He took a little pause before speaking.

There is a park near my house.

There is a park near my house.