Student or Learner
a. I was looking for John. I couldn't find him. I went all through the office and he couldn't be found. And then finally, there was John at main entrance.
b. Look at this photo. There is Pete at the window and there is your brother at his desk.
c. Look at this photo. There is Pete, at the window, and there is your brother, at his desk.
Do the above sentences work?
John has to be at the main entrance. Other than that, both narratives are fine.
I am not a teacher.