"The kitchen is hers."

Translation: La cucina è la sua.

[ejbkt]

Why is "la cucina e lei" not correct?

[Viaggiatore]

The kitchen is her?

[charlesfredy]

I cannot be "e la sua cucina"?

[Lavmarx]

Is "La cucina è della." wrong?

[karen.cosm]

what is difference between sue and sua

[Lavmarx]

Sue is plural, sua is singular.

[topdog17]

"La cucina è la sua" is the correct answer it says, but is "La cucina è sua" correct too? Because I just answered one (incorrectly, apparently):
It told me that "The knife is ours" = "il coltello è nostro" and not "il coltello è il nostro".
Are there special rules when it comes to plurals? Or is this an error? (you can see it here) https://www.duolingo.com/comment/402781

[JosephineS11]

I cannot use accents on my mobile

[Paulixtoja]

Can somebody explain what is the difference between "la cucina è la sua" and "la cucina è sua"? Both answers are accepted by Duolingo, but do they mean exactly the same?