He's not the only person who can be President and do a great job.
In fact, you are the only person who has turned up.
He was about the only person here I could talk to.
But a woman in black was the only person I saw.
Could they not see he was the only person in the car?
She's the only person he wants to tell about the money.
She must be the only person on the water right now.
No, the child must be the only person in the photo.
Was she the only person in the world who didn't know everything?
Perhaps the only person left who knew the real him.