Is Federico a brother?
A brother of whom? His wife, by the way, later got the lead in One Day at a Time.
Dave and Nate
Nope, just an employee, at least originally
Because one of them said "dad" to him. (I Did not mean call him dad ).
Saying "Dad" is a short version of "my dad".
I usually only say "dad" to someone if it is our collective dad. Otherwise I say "my dad"?
Yah, I got that impression. You're probably in the minority on that, at least in America.
To whom?