With an accent over the first 'i', and a comma after, it means:
'Yes, you are//he/it is mine'
Without the accent and comma, it means:
'If you are//he/it is mine'.
if you have msn, mine is...
"Si es, es" is Spanish for "If it is, it is". If you just mean "si es", that means "if it is". If you mean "Sí es" (with an accent on "Sí"), it means "Yes, it is".
It means "[it] is mine"
Is mine and that
the world is mine
oh my God!!
This telephone is mine.
"Si fuero mío" is incoherent. You likely meant "Si fuera mío", which means "If it were mine". "Si fuero mío" literally means "If charter mine"
"El mio es tuyo" means "mine is yours" in Spanish. It is a phrase used to express sharing, generosity, or solidarity with someone.
el gusto es mio = the pleasure is mine
El placer es mio.
"Si hoy es jueves, mañana es..." means "If today is Thursday, tomorrow is..."