A riddle

[CoolBees]

A man goes to the hospital to visit someone there. The nurse tells him, "Sir, only immediate family members are allowed to visit this patient"

To which the man replies, "Brothers and Sister have I none. But this man's father is my father's son."

Did they let him in? ... and what was his relation (if any) to the patient?

[Michael Bush]

I don't know if they let him in... but they should.

Well... Let's identify the people.  We have the speaker and the patient.  So the speaker says the patient is the son of a son of the speaker's father.  If he said nothing else that would make him either a nephew or a son.  But since the speaker says he has no brothers or sisters, that would narrow it to one possibility which is that the patient is the speaker's son.

[CoolBees]

You got it. 

It's a fun one to give to kids, and watch their heads wrap around it. 

[BeeMaster2]

 

[Michael Bush]

The one I used to hear when I was a kid was the riddle "There is a man.  He is not my brother or sister, but he is my father's son.  Who is he?"  Which is a somewhat similar riddle.