Have either of you seen my pen?
1- Has either of you seen my pen?

On attempting to restore the picture to its original condition, almost irreparable change was discovered.
2- On attempting to restore the picture to its original condition, irreparable change was discovered.

I was annoyed arriving late, also his rather insolent manner put me out of temper.
3- I was annoyed at arriving late, also his rather insolent manner put me out of temper.

He is anxious not only to acquire knowledge, but also eager to display it.
4- Not only he is anxious to acquire knowledge, but also eager to display it.

People have and still do disagree on this matter.
5- People have and still disagree on this matter.