Hi,
What is the difference between "I am home" I usually say this to my wife when I arrive home, when I come through the door.
and " I am at home. I say this if I telephone someone and they ask me 'Where are you phoning from?'
; "I stay home.'and "I stay at home"? There's not much difference here, it's just that 'at' is often omitted. Where I live, I usually say and hear 'I stay home'.
Best wishes, Clive