There is no particular reason for keeping a watch upon that book.

He wanted to keep an eye upon his enemy's son.

But they need not keep such a check upon us.

My next step was to keep watch upon the three of you.

That he kept the plans upon him at all times.

He kept his eyes upon them to make sure they understood him.

He would keep his mind upon it all the time.

But it would be best to keep an eye upon them.

Indeed, within certain lines, he had the right to keep an eye upon her as his charge.

Keep the guard upon the run until the work is done!