stay up *
sit up **

The fight to stay up looks like being a long one.

If the game went the other way, well, I would not want to stay up for that.

Sometimes I close my eyes and remember the way we used to stay up half the night talking.

For one thing, Clinton now seems likely to stay up.

I'm having all I can do to stay up with her.

I should not have asked you to stay up here.

They could also simply stay up for the time being.

I just want to stay up here for a few minutes more.

It wasn't like her mother to stay up so late.

We were going to stay up, watch a late movie.