I might be wrong, but I think your question pointed to what is called Tag Quesitons, such as "John is not here, is he?"
If I am wrong, and you had no intention of asking about that, then save your time and don't read the rest of my message, otherwise, if you actually intended to ask about that...
Spanish is much easier, than English in that respect:
You can always use "¿no es cierto?" o "¿verdad?" o "¿correcto?"
John is not here, is he?
John no está aquí, ¿verdad? (or any of the other)
Sergio will come tomorrow, will he not?
Sergio vendrá mañana, ¿no cierto? (or any of the other)
I was right, wasn't I?
You estaba en lo correcto, ¿no cierto? (again, or any of the other)
I hope this helps.
Cheers,
Mario