"Which of these is yours?"
Translation:Quale di queste è tua?
Il tuo, tuo, la tua and tua all work. The trick is pairing the rest of the words in the sentence to match the gender you picked.
If you use (il) tuo then it must be accompanied by questi. With (la) tua you must use queste.
Quale cannot be replaced with quali because the English sentence indicates you are only looking for one: Which (one) of these is yours?
Hope that makes sense :)
Yes, that helps with the quale but I did not have questi and il tuo accepted . If part of our sentence is correct eg we have used a masculine where this is acceptable but there is another mistake in the sentence, would it not be possible to give that part as an acceptable alternative. (Otherwise we are left puzzling over why it MUST be feminine)