Niedziela form help.

I have sort of asked this before but I am needing some clarification.

If somebody were to ask "Sunday?" as a single word clarifying question is it still "w niedzielę?" or is just "niedziela?" correct. If it matters its more asking "do you mean on Sunday?" as if maybe they didn't hear the day you said.

Either.

So is it different if you are just asking if they mean "Sunday" in general or if you are asking if they mean "on Sunday?"

Imagine this exchange:

A: "We need to go to Paris"

B: "Someday"

A: "Sunday?"

The form of Sunday is all I am worried about so no need to translate the whole thing.

Thanks for the trouble.

It would take long time to explain so I will only advise you to stick with w niedzielę.

"Niedziela" is Nominative. "W niedzielę" is Accusative. Why it's "niedzielę", not "niedzielii" in the Dative resp. Locative, I'm honestly no longer sure-:) ALL weekdays though follow the same pattern:

w niedzielę
w poniedziałek
we wtorek
w środę
w czwartek
w piątek
w sobotę

If you wanted however to indicate "Until Sunday", i.e. "See you (formal or familiar) Sunday!", the form would be "Do niedzielii!", same ending as in the Dative and Locative-:) "Niedziela" is feminine. The other weekdays, respectively:

Do poniedziałKU!
Do wtorKU!
Do środY! (also feminine, like "niedziela")
Do czwartKU!
Do piątKU!
Do sobotY! (fem.)

-:)))