Why is 'jaká' used here instead of 'co'? The question that would seem to be implied with 'jaká' (for those of us who don't yet understand the idiomatic nuances of Czech) is 'What are your daughter's names like?'
How would one ask, what are your daughters called? Jméno means name so I'm not sure this translation should be incorrect!
That would be "Jak se jmenují vaše dcery?" (and many other variations, obviously - currently 35 of them, that are accepted).
Proč nejde: "What are names of your daughters?" , když "names" je množné číslo?
Může být i "What are your daughters' names?" ?
Why used here tvých
Why not tvoje
It is the genitive case, OF ... daughters.